Woah! That's surprising. Do they offer that for a specific plan? From SDN boards i get the feeling the class itself isn't that helpful, but their online stuff might be. What did you think when you were using kaplan?
I didn't take the Kaplan but there are dangers of doing the Kaplan if you are busy the semester where you are planning on taking this prep course because it is a "do it yourself" program. If you study hard you will be successful but you have to motivate yourself. But if you use Princeton Review, you will have a lecture and there will be someone constantly motivating you. I would choose Princeton Review over Kaplan if your area has that option.