The Princeton Review provides standardized test preparation for those who are about to take the SAT as well as other standardized tests for graduate schools. Although their tutors all score really high on the tests on which they instruct, there is still considerable variation as to the quality of the instructor although this will be true of any company.
I used them to study for the SAT's. My score jumped a lot, but I'm not sure how much of that I can attribute to them. The biggest help was having the opportunity to take 3 full length standardized tests under normal testing conditions. I felt the classroom sessions helped, but weren't that informative. I'm not sure if they have recently revamped their program to take advantage of the internet and computers more, but when I took it, it was only the classroom and textbook.
Although it is an imperfect comparison, I think I would favor Kaplan over Princeton Review given the amount of preparation material and resources that were made available
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