Hi guys - creating this topic so that no else makes my mistake! I purchased Princeton Review's self-study program to try to boost my GRE quant scores from my first score of 156. After using their program for 2 months I started to hit my target Q scores (163+) on their practice tests and even scored a 166 Q on my final practice test. On my second GRE attempt after using Princeton Review for 2 months and completing 90%+ of their quant modules and 5 of their practice tests I scored a 158. 2 points higher. Honestly that difference could just come down to a variation in tests between the days.
I emailed Princeton Review asking for my money back because they have a score guarantee, but because I hadn't completed every single module and my score had improved those two points I didn't qualify for a refund. I can honestly say this is probably the worst waste of money in my life. Please be careful before paying hundreds of dollars for online test prep!