GMAT Strategy

Hello everybody -

My test is less than 2 weeks away and every time I take a practice test my scores seem to be all over the place. Whenever I hone in on something, it seems that I do poorly on the other sections. I have completed the general study schedule (hit the infinite math sections as well as RC, CR, SC and IR/AWA) so now I'm just trying to figure out why my scores change so much.

GMAT 1 (first try) - 650 (Q 42/V37)
MGMAT 1 - 640 (Q43/V34)
GMAT 2 (first try) - 670 (Q45/V37)
Kaplan CAT 1 - 700 (Q49/V39)
Kaplan CAT 2 - 690 (Q50/V33)
MGMAT 2 - 640 (Q40/V37)

I know that each company does their own CATs a little differently, but I was happy with my progress getting up to a 700 until my most recent MGMAT test, where I got yet another 640 on their CAT. Both Quant and Verbal seem to be kind of random, so I was wondering what you all thought about the trends I'm showing.

Now I know that these scores aren't TERRIBLE, but I'm aiming for a 720 to be competitive because I am lucky enough to have a high GPA and solid work experience. I crushed my SATs and ACTs so I'm kind of frustrated that I can't reach my goal. Thoughts would be greatly appreciated!