I took both berkeley and princeton, studying with EK books right now. I can honestly say that while prep course make you feel good by giving you lots of information and concepts, doing well on the mcat also requires good reading skills and a luck (a big factor). By luck i mean the right passages on the real thing, no problems during the test and just a good day overall. So my biggest advice to you guys is esp. to those overly anxious premeds. DO NOT WORRY TOO MUCH. (I did NOT say RELAX). Although this advice maybe obvious and trite, I wished I heeded when going through this process. Berkeley have great teachers but do not know the test enough. Princeton have slightly less better teachers in chemistry, but good bio and physics teachers. (at least here in westwood) I would rate them about equal overall. Examkrackers is more honest about what is and what isn't on the MCAT. While some people say Berkeley is all that, Princeton's the best or EK is a godsent, I think the perfect prep course would have Berkeley's enthusiasm for teaching, Princeton's rigorous curriculum and books and Examkracker's honesty and experience of the test itself.