Overall good. The Math section is great - very spot on.

I was very careful in choosing my practice materials as I was afraid studying a sub-par material would hurt my actual test performance. For that reason, I predominantly used Official Guide for my practice. After a few months, I've exhausted all the practice questions from several editions of the Official Guide. I decided to take a chance with GMAT Club Tests. It was a good leap of faith. Overall the GMAT Club Tests are good. I especially like the Math section. My Math raw score was already 40-45+ when I finished all OG practice Math questions, and it was really hard to find good practice test to boost my score to 49-50, which was my goal. GMAT Club Tests Math section did the job. I eventually got a 50 raw score in Match section in my real test, and found the Math questions in the real test to be very similar to those in GMAT Club Tests. Besides the obvious option which is practicing OG questions, I would recommend every GMAT candidate to do GMAT Club Tests, especially to the candidates who are in the 700-ish range and want to get to a higher score level.