This is really not newfocus. I am his lazy roomate who cannot sign in himself. Seriously, I have had experience with both and have found that Kaplan's material is more indepth and princeton sticks to the basics so they can spend more time on your test taking skills. If the test itself is the problem take princeton. If the material is the problem take kaplan. Everybody I know that has taken princeton says it helps. Kaplan people say they don't think it makes a difference. Plus princeton will let you retake the course if you don't get the score you want. I improved my score 6 points with princeton review.
Kaplan, Kaplan, Kaplan.
I took it and went up 12 points. Kaplan's practice tests and test 'library' give you plenty of test taking practice. Kaplan's questions are also very similar to the actual MCAT. Friends who took Princeton didn't have a great experience.