Hi GMAT717,
When you take a CAT, if your goal is to receive a realistic score assessment, then you really have to be strict about HOW you take the CAT. The more the 'CAT-taking event' deviates from what you'll face on Test Day, the more likely the score is to be inaccurate (and in most cases, that means "inflated"). As such, you should make sure to take a NEW CAT each time, with the Essay/IR sections, away from your home, at the same time of day as your Official GMAT, etc. Since there are many aspects to taking the GMAT that you can only learn by taking a CAT, you shouldn't wait until the very end to be taking CATs - you should be taking them at regular intervals throughout your studies.
Beyond those details, it's important to remember that taking lots of CATs will NOT make you a better Test Taker. A CAT is really a 'measuring device' - when used correctly, it will give you a realistic score and help define your strengths and weaknesses, but it will NOT help you to fix any of those weaknesses. To raise your scores, you have to put in the necessary practice and repetitions. The CAT will show you whether your studies are helping you to improve or not. As such, you really shouldn't take more than 1 FULL CAT per week.
1) How many CATs have you taken so far and how have you scored on each (including the Quant and Verbal Scaled Scores)?
GMAT assassins aren't born, they're made,
Rich