Hi starklogan456,
At higher-and-higher score levels, points can be won and lost rather easily. All four of these CAT Scores are outstanding Scores, so assuming that you took these CATs in a realistic fashion that matches what you will face on Test Day, then you are a really strong overall critical thinker. The variations in your Quant and Verbal Scaled Scores are almost certainly due to a handful of little mistakes and lucky/unlucky guesses on each Exam. As an example, if you review either of the CATs in which you scored 720 - how many questions in the Quant section did you get wrong that you COULD have gotten correct? How many Verbal questions did you 'narrow down to 2 choices' but still get wrong? What would you have needed to do differently to avoid those little errors and pick up those points (hint: some additional note-taking would almost certainly be required).
Since you're so close to Test Day, you should NOT be trying to do too much studying (so NO CATs and NO "cramming"). Some light practice and review would be fine, but you would be better served by getting some extra rest - so that you can go into Test Day calm, clear-headed and ready to work.
GMAT assassins aren't born, they're made,
Rich