The official guide to courses by Straighterline, Study, et al: We want YOUR input!

[MNomadic]

Provider: Online Degree
Course: Intro to Computer Science 101
Course content: Main videos and some lessons have supplementary videos that are less than useless, there's an embedded timer preventing you from moving on until the timer ends. There are also quizzes that include questions unrelated to the content of what you're learning and instead ask you arbitrary things like, "Which framework did I use to demo this concept?" or "Which of the following is NOT an example I provided in class?"
Final exam format: 47 multiple choice questions from the quizzes
Final exam content vs course content/practice exams: Questions were pulled directly from the quizzes and since some ask arbitrary things, it's a poorly implemented test.
Time taken on course: I actually did a few lessons years ago when OD first came out, then they reworked the whole class from scratch(made it worse) and I did a few more lessons a year and a half ago. Then I did the other 80% of the class over the last week on a whim since I was practicing Python.
Familiarity with subject before course: Took a few basic CS courses before that used Python. Also, have an IT degree that introduced me to a lot of the concepts. I took this on the tail end of a 2-week python BootCamp I was doing for personal enrichment. Despite all that, you still have to view the lessons(I paused and scrolled), since they ask arbitrary things that wouldn't normally be part of an actual CS curriculum. 
Pitfalls, high points, things others should know: This is a piss-poor course. Besides the usual shortcomings of OD(unskippable videos, no way to see your grade until you already take your final) the class itself is poorly written and includes very little in the way of learning CS or programming, has extremely long, slow, boring (unskippable)lessons, and is just poorly implemented. In fact, speeding the lessons up to 2x still felt slow or normal speed at best.
1-10 Difficulty level: 10 only because the class is terrible. I had the video pages open in the background while working on other stuff and skipped to the quizzes when it let me because I wanted to see if the quality ever improves. Spoiler alert, it doesn't. Want to learn python, CS, or programming? This course is not for you. Already know Python/CS/programming and just want to "test out" of a course for cheap? This class isn't for you. I can't think of any situation where this class would be a good option for someone unless they absolutely had to get the absolute cheapest credits on the subject possible, couldn't do Saylor, and don't actually need/want to learn CS or programming. 

I passed with a 92% though I didn't need the credit.

[jsd]

Provider: Online Degree
Course: Intro to Computer Science 101
Course content: Main videos and some lessons have supplementary videos that are less than useless, there's an embedded timer preventing you from moving on until the timer ends. There are also quizzes that include questions unrelated to the content of what you're learning and instead ask you arbitrary things like, "Which framework did I use to demo this concept?" or "Which of the following is NOT an example I provided in class?"
Final exam format: 47 multiple choice questions from the quizzes
Final exam content vs course content/practice exams: Questions were pulled directly from the quizzes and since some ask arbitrary things, it's a poorly implemented test.
Time taken on course: I actually did a few lessons years ago when OD first came out, then they reworked the whole class from scratch(made it worse) and I did a few more lessons a year and a half ago. Then I did the other 80% of the class over the last week on a whim since I was practicing Python.
Familiarity with subject before course: Took a few basic CS courses before that used Python. Also, have an IT degree that introduced me to a lot of the concepts. I took this on the tail end of a 2-week python BootCamp I was doing for personal enrichment. Despite all that, you still have to view the lessons(I paused and scrolled), since they ask arbitrary things that wouldn't normally be part of an actual CS curriculum. 
Pitfalls, high points, things others should know: This is a piss-poor course. Besides the usual shortcomings of OD(unskippable videos, no way to see your grade until you already take your final) the class itself is poorly written and includes very little in the way of learning CS or programming, has extremely long, slow, boring (unskippable)lessons, and is just poorly implemented. In fact, speeding the lessons up to 2x still felt slow or normal speed at best.
1-10 Difficulty level: 10 only because the class is terrible. I had the video pages open in the background while working on other stuff and skipped to the quizzes when it let me because I wanted to see if the quality ever improves. Spoiler alert, it doesn't. Want to learn python, CS, or programming? This course is not for you. Already know Python/CS/programming and just want to "test out" of a course for cheap? This class isn't for you. I can't think of any situation where this class would be a good option for someone unless they absolutely had to get the absolute cheapest credits on the subject possible, couldn't do Saylor, and don't actually need/want to learn CS or programming. 

I passed with a 92% though I didn't need the credit.

You weren't kidding.

I decided to knock this out this weekend. If I didn't have a basic familiarity with Python already, this certainly wouldn't have helped me get one. Some of the topics the course gets into are a bizarre choice for an intro to programming course, and have very little to do with python. The "Cloud" section literally felt like an advertisement for his favorite products. And then there was stuff completely skipped that is pretty important to know... For example, did he even talk about list slicing? He touched on classes but didn't explain OOP at all. Just weird choices on what to include.

The questions, as you stated, are a joke. Some of them were seriously stuff like "Did I use a restaurant analogy in this lecture?" as opposed to a question actually relevant to the concepts being taught. Bizarre.

I disagree with you in that I would say if you just need the credits and already know the material, it's worth the $9 to grab them here (honestly everything I hear about Saylor seems like you'd run into similar or worse issues with them). You just have to have the patience to sit out the obnoxious lecture clock (or figure out how to disable it ). The course is pretty easy if you can get over the dullness and that stupid clock.

[AllThose299s]

Provider: Study.com
Course: Geometry 101: Intro to Geometry

Course content: Text & Videos 
Final exam format: 60 multiple choices
Final exam content vs course content/practice exams: Have you seen the information before in the course, or was it a total curve ball?
The final exam content seemed on par with the course content. The curve ball was the fact this final was only 60 questions, after taking different sdc finals I was accustomed to the 100 question finals. Scored better on the final compared to the 5 practice final exams I took.
Time taken on course: Hours? Weeks? Days? About two months... This was the course I was attempting to complete during my first attempt at Computer Architecture a year ago (which I was about 2/3rd done with all the quizzes back then) and after completing Computer Architecture & Discrete Math recently, I figured I should be able to knock it out quickly (however I spent at least a full month just focusing on trying to remember the 2/3rd parts I completed previously and taking a bunch of practice finals).
Pitfalls, high points, things others should know: Comparing to where discrete math covered a lot of different topics, Intro to Geometry covers a lot of different topics within geometry so at some point you start to see how things line up from previous chapters and you aren't feeling lost compared to some of the more painful chapters from discrete math. 
However, there is a lot (and I mean a lot) of quizzes, near 130 quizzes. If you can avoid focusing on other courses and just focus on geometry and if you can avoid the almost year break that I took, then if feel like you are solid with everything you've covered and do well on a couple practice finals then you should be good.

I'm positive that the bank of questions that they have in the practice finals & quizzes is *huge* because by the time I took the final exam, the only topic which felt might have been repeated from the 5 practice finals I took was related to the non-euclidean geometry (which only has 3 lessons anyways so you would expect that). I can guarantee that the final will include a few questions on 3D Geometry.

1-10 Difficulty level: 8-9.

[AllThose299s]

Provider: Study.com (Originally I started the Calculus course on StraighterLine but I dropped it after the first graded exam)
Course: Math 104: Calculus
Course content: Text & Videos 
Final exam format: 60 multiple choices
Final exam content vs course content/practice exams: Have you seen the information before in the course, or was it a total curve ball?
A majority of the content in the final (at least for me) seemed to be based off last 4 chapters, however while the last 4 chapters might still be fresh in your mind by the time you take the final, it still pulls enough questions from the other chapters to make an impact on your exam results. Chapters 14 & 15 (Integration Applications & Differential Equations) were critical for me to be able to pass the final, which is a shame because I found myself watching random youtube videos to just to attempt to find a way to pass the quizzes for those chapters because either the content in the lessons or the quizzes for those chapters were just so poor.
Time taken on course: Hours? Weeks? Days? In total I spent over 2 months on Calculus, as far as the amount of time spent on SDC's Calc course: 1 month fully dedicated.
Pitfalls, high points, things others should know:
Spent a full month learning what I could learn from StraighterLine's Calculus on via Professor Burger, watching Gil Strang's MIT OpenCourseWare Calculus videos on youtube and reading Calculus Made Easy by Silvanus P. Thompson via https://calculusmadeeasy.org in 2021. I tried watching Professor Leonard on youtube as well however they were just too long. I enjoyed the Prof. Burger's lessons on StraighterLine and personally if I could have had a combination of Prof. Burger's lessons with the most of the quizzes & final from SDC, that probability would have been the best experience.

I found that StraighterLine's practices problems seemed disconnected with the actual lessons and sometimes it took over 20+ attempts until I felt confident enough to move on to the next section, even using a Ti-Nspire w/ CAS graphing calculator, a casio fx-115es plus scientific calculator (which is what I used for SDC) and the NumWorks calculator emulator on my phone I was unable to pass the first graded exam on StraighterLine with multiple attempts.

Moving on to SDC in 2022, the first half of the quizzes went super quick and I had no trouble at all until I got to the second half were it started to drag me down. At some point the quizzes start to not match the lessons and where other courses would at least explain how to solve the questions when reviewing the quiz results, some of the quiz explanations ended up giving what seemed like riddles and some where just blank. I would only recommend the course as a last resort.

1-10 Difficulty level: 10.

[MNomadic]

Provider: Study.com
Course: Math 104: Calculus
1-10 Difficulty level: 10.

Congrats! Calculus isn't an easy class no matter where you take it and that class alone discourages many people from pursuing a lot STEM degrees. 

Instead of giving up when SL didn't work for you, you pivoted to a different format and incorporated external sources to push through!

[muu9]

Provider: Study.com
Course: Computer Science 105: Introduction to Operating Systems
Course content:  Video, with transcripts
Final exam format: Dunno
Final exam content vs course content/practice exams: Have you seen the information before in the course, or was it a total curve ball?  
Time taken on course:  Hours?  Weeks? Days?
Familiarity with subject before course: Enthusiast
Pitfalls, high points, things others should know:  There's some "half-truths", such as saying dual core processors are twice as fast as single core processors, however the quizzes are directly based on the content covered in the lesson. They can be "gameable" at times - one of the question's answer choices were xcopy, ycopy, zcopy, and copyx. You don't even need to know the question to figure out what the answer is.
1-10 Difficulty level: 2-3

[deeznoots]

Provider: Study.com
Course: Physics 111
Course content: There are 128 videos and quizzes. The quizzes have 5 questions, u can retry them 3 times.   
Final exam format: 100 questions. You get 2 hours to complete. Youre allowed to have paper and a calculator 
Final exam content vs course content/practice exams: I felt like the course content didnt prepare me for the final. The final was completely different than the practice exam. I got a 90% on the practice but failed the final. 
Time taken on course: 4 days, but i didnt do anything else in those 4 days other than the course. You can complete it in two weeks if ur not in a rush
Familiarity with subject before course: Ive never taken physics
Pitfalls, high points, things others should know: Take the course elsewhere. It is not worth it. Although you only need 56% on the final (if u do all quizzes), the questions will go over your head if youre not familiar with physics. I found myself forgetting the things i learned from the first lessons. There is just too much content that you have to remember 
1-10 Difficulty level: 8

[withrown]

Provider: Saylor
Course: POLSC 101
Course content: Lots of modules with externally linked reading sources as well
Final exam format: 50 questions multiple choice
Final exam content vs course content/practice exams: Definitely covered the same material but questions were slightly reworded and more questions on particular theorists.
Time taken on course: 3 hours but - I'm getting a masters in policy and read a lot of journals.
Familiarity with subject before course:   a lot of readings and research on the topic previously.
Pitfalls, high points, things others should know: for 5 dollars give it a shot
1-10 Difficulty level: 3-4.  take the practice exam and look up the answers for the questions you miss

[MidLifeCrisis]

Provider: Saylor
Course: POLSC 101
Course content: Thorough. Lots of readings broken down into 6 units. 
Final exam format: 50 questions. Multiple choice with 4 answers. 
Final exam content vs course content/practice exams: It was all in there. 
Time taken on course: Not long. Did it all in one evening. 
Familiarity with subject before course: Not politically inept. Have a pretty good understanding on systems and processes. Weak on specific thoughts of people (eg. What was John Lockes view..)
Pitfalls, high points, things others should know: If you have a reasonable knowledge you'll be fine. The practice exams weren't shockingly different from the credit exam. Knowing theorists will help you. To give you an idea I got 80%. It is slightly US centric (maybe 5 questions) but there's nothing outrageous. 
1-10 Difficulty level: 3. Id say 5/6 if you are coming from no knowledge. 

Its definitely not Sophia, I'm hoping it will transfer into UMPI for POS 101 and for $5 its worth trying.
I cherry picked and speed read material for a few hours, did the practice exam, did the credit exam and got 80%. If you gave yourself even a week its totally achievable to get solid scores.

[MidLifeCrisis]

Provider: Saylor
Course: POLSC 221 - Intro to Comparative Politics
Course content: Thorough. Lots of readings and a few videos broken down into 7 units, each of those have a few subunits. 
Final exam format: 50 questions. Multiple choice with 4 answers ea. 
Final exam content vs course content/practice exams: Reasonable. 
Time taken on course: 8 Hours - Passed.
Familiarity with subject before course: Not politically inept. Have a pretty good understanding on systems and processes. Weak on specific thoughts of people (eg. What was John Lockes view..)
Pitfalls, high points, things others should know: Being comparative this you start with some real basics (what is science, how it applies to politics etc) and do some theory but there is then some real world comparisons done and this is reflected in the exam which has questions about countries situations etc that was directly referenced. If you look at the presidential vs parliamentary systems, youll also need to know that in a list of X, Y and Z that Z is the parliamentary system.
There were a couple of broken links, but with a bit of google-fu it was easy enough to find what they were after, or skip it. 
1-10 Difficulty level: 4. Id say 5/6 if you are coming from no knowledge. 

Saylor gets a bit of a bad wrap on here and I can understand why. I think though that for the $$ ($5 for the exam) its not a bad way to get some credits, especially if you have some familiarity with the topics, although if you are completely Green then I think it could get overwhelming.