I bought this with Cracking the GRE to prepare for the test. I'd say it helped me (my boyfriend said "wow" when I told him my score). It has plenty of quizzes for good practice, and they do a great job of explaining the testing process to you. The strategies might take a while at first, but over time it gets easier to process faster. What I didn't like, though, was that beyond the quizzes, nearly everything is identical to the verbal and writing sections of Cracking the GRE. The vocab hit lists are exactly the same- I would have liked some new words.

The math on the GRE is pretty simple, so if you want test prep, I'd suggest getting this book only, and get free math prep from the ETS website.