Hi aniasok,
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function (and that you took your CATs in a fashion that matches-up with how you will take your Official GMAT), your various CAT score results show that you essentially performed the same each time (about 630 +/- a few points). You handle certain aspects of the GMAT consistently well, but you also make certain consistent mistakes. As such, there is a reasonable chance that you you will score at that same general level if you take the Official GMAT in a week's time. If you plan to continue studying until you score 700+ (or close to it), then you might want to consider pushing back your Test Date. There's no harm in taking the GMAT as scheduled, but you could potentially save some time, money and frustration by giving yourself additional study time.
There are some additional factors to consider. From what you've described, your studies so far have been "book heavy"; unfortunately, many GMATers who study in that way end up getting 'stuck' at a particular score level. Even the best books are limited in what they can teach you; they also can't force you to approach questions in a certain way and their explanations are often one-sided.
In addition, you have to be careful about confusing "quantity" of study with "quality" of study. I've never asked anyone to study 30+ hours a week - and while it's great that you might have the available time to study that much, with that number of study hours, you would run the risk of 'burning out' before Test Day (and that is something that might have already happened). If you are going to try to study that much, then I suggest that you take one hour "off" for every two hours of study. For example, you could study for 2 hours, then stop for an hour, then study for another 2 hours, then take an hour off, etc.
"Review" is an exceptionally important part of the GMAT training process; your ability to define WHY you're getting questions wrong is essential to defining the areas that you need to work on (and the specific things that you need to 'fix'). As such, I'd like to know a bit more about your last CAT. While a full Mistake Tracker would provide a lot more information, there are some basic questions that you should be able to answer (and the more EXACT you can be with your answers, the better):
After reviewing each section of this recent CAT, how many questions did you get wrong....
1) Because of a silly/little mistake?
2) Because there was some math/verbal that you just could not remember how to do?
3) Because the question was too hard?
4) Because you were low on time and had to guess?
5) How many Verbal questions did you 'narrow down to 2 choices' but still get wrong?
GMAT assassins aren't born, they're made,
Rich