MGMAT CATs, GMATPrep ...what else?

If you saw 4-5 questions that you actually recognized (you knew the right answer AND could just put it in without having to work on the problem), then your score is probably fairly inflated. It would've helped you not just on the ones you recognized but on others for which you'd have more time because of the time you "saved" on the ones you knew.

For others who have exhausted tests from a particular source and risk getting repeated questions as you continue to use that source, do this: if you see any questions you recognize well enough to know the answer, go ahead and answer, but look at the clock and then sit there and wait the full 2 minutes before you go on to the next question. At least, that way, it won't help you on other questions.

And, of course, if you see something you sort of recognize but you don't really remember it, then go ahead and do it the way you normally would - but, again, make sure you don't answer it in a minute just because you remember some stuff. Take the full time on the problem.

Question: how often are you taking practice tests? I generally recommend one every 3 weeks roughly. A practice test is useful if you analyze the results and use those results to set up a study plan based on your strengths and weaknesses. It can easily take 2-3 weeks to work through everything you should be finding from your test results. It's only marginally useful to take tests frequently without the analysis and in-depth study. (And perhaps that's not what you're doing - I just want to make sure, because most people study for 3-4 months and, as such, only need a total of about 4-5 exams, maybe 6 at the outside.