So I had already taken the test once about a month ago using Princeton Review materials, and scored a 680. My Princeton Review practice tests were all between 670-730, so 680 was slightly disappointing for me. My goal was really 700+, and my verbal score was always holding me back. So I decided to dump the materials, and do an independent study with MGMAT materials instead.
Totally glad I did. I think MGMAT focuses much more on some of the harder techniques, so you can really improve upon skill deficiencies.
MGMAT1: 710 (48Q, 39V)
MGMAT2: 730 (48Q, 42V)
MGMAT3: 720 (49Q, 39V)
MGMAT4: 750 (49Q, 44V)
MGMAT5: 750 (51Q, 41V)
I stopped taking practice tests once I started exhausting the 700-800 level math questions. Relative to PR, I'd say the math was much more difficult, which helped for pacing purposes since the first time I took the GMATs I found I was really pushed to hurry along. Getting used to difficult questions made the real test seem slightly easier in comparison. PR had me consistently at 51Q, 99% on all my practice tests-- which I think was NOT representative of the actual exam.
When my verbal score started improving drastically on all my MGMAT practice tests, I was skeptical that the MGMAT actually mirrored the actual exam since Verbal has never been my strong suit. But ended up scoring 99% on the actual thing thanks to some really focused SC studying. (I didn't really study RC and CR that much, because I found that SC was the most reliable area in which very analytical people like me could improve. I like studying rules).
Good luck to people taking it! And for people planning to retake-- definitely go for it. Thanks to MGMAT for a great set of materials!