Well .... many here seem to have positive experience with CATS in relation to err... advanced ratings. Maybe CATS have more extensive material for those, but it still points towards a positive experience.
I will keep CATS as a primary study material, Pooley's as the more extensive material, and AIRQUIZ for the question bank. I would know in a few weeks if this strategy works for me. I plan to take Air Law, Meteorology, and Operations first.