I just finished taking the GMAT. My 760 is right in line with my GMATPrep practice test score:
GMATPrep Practice Test #1
Quant - 49
Verbal - 47
Total score 770
GMAT actual test
Quant - 49 (88 percentile)
Verbal - 42 (95 percentile)
Total score 760 (99 percentile)
I did not do any studying or preparation before taking the practice test or between the practice test and the actual. (I'm going to keep my job during my MBA program, and none of the local schools have strict entrance requirements.)
What I would do differently: Better time management on the real test! On the practice test I monitored my time and finished each section with about 1 minute left.
On the actual test I ran out of time on the Quatitative section and had to guess randomly on the last 5 questions. On the actual test verbal section I worked faster than I needed to, and completed the section with 6 minutes to spare.
Hope this helps others who are preparing for the GMAT!