Practice scores
Kaplan Diagnostic: 630 (35Q, 42V)
Kaplan CAT #1: 630 (37Q, 42V)
GMATPrep: 690
Then I got sick of studying and taking practice tests, so I quit going to the Kaplan classes (it's helpful but not nearly worth the money anyway). I flipped through a couple Kaplan study books and went over some of the math formulas the last few days before the GMAT.
Real scores
GMAT #1: 620 (36 Q, 41V... or something like that). I was exhausted the evening of the test from having to work that morning and not getting much sleep the night before.
I rescheduled to take the exam 6 weeks later. I didn't do any further studying or practice questions. I spent a few minutes the night before refreshing my memory on some of the math equations. I took the exam at 8am after a good night's sleep.
GMAT #2: 730 (44 Q, 47 V).
For what it's worth.