Correct me if I'm wrong, but...

[irnbru]

I agree that mixing and matching source material to suit your own learning style is the best approach. That's why the specific exam feedback section is gold.

The free-clep-prep website is a nice site although as it's the majority result of one guy's work, who hasn't sat all the tests, it doesn't quite match up to the power and depth this forum has. I would definitely recommend that site to someone starting out or thinking about options it as it's almost a replacement for Lawrie's bain4weeks site with regards to the grading of tests. Just in case there's any doubt, that should be taken as a strong recommendation

Instantcert is massively focused on the tests it covers. The advantage here, is that what you learn has direct relevance to the test; you're unlikely to spend an hour or two getting side-tracked into reading and researching topics outside of the test syllabi. In my experience, for the Humanities CLEP, this was absolutely key. A dozen times so for the GRE Test. Coupled with the forum which helps keep people targeted, I'm under no illusions that I would have made the progress I have in absence of this forum and IC.

Scepticism is good in appropriate doses. Being able to draw from the experience of other people is extremely valuable. The capacity for interaction and feedback should make the journey smoother and getting as much information and relevant resources and material is common sense.

edit: free-clep-prep - Sorry che