I'm taking TPR for a second time:
materials: Great, supply you with plenty of reading material, and plenty of practice passages, free-standing, practices tests
cust. service: i guess it depends on where you are, because mine isn't too bad, but then again not too great either
instructors: hit or miss, this is my 2nd time taking this course, and both times i've gotten a Gchem instructor who although may be brilliant in the subject, has a very hard time getting the message across (in understandable english). Some of their teachers know the topic, and some know the mcat
the difference is, if you ask a teacher that knows the topic a deep question about it, they can use their knowledge to answer it, but the teachers that only know the mcat, will only have the knowledge relevant to the MCAT. I know that since we are taking the MCAT, that should be the only thing we want, but sometimes to explain some weird (or complicated) topic, you need a better "foundation" of understanding the topic...
I heard bad things about Kaplan, and I would've done berkeley review if it were closer to my house