I just got my score back and thought I should share since this tread has brought a lot of comfort in the last month.
I took the Jan. MCAT after 3 months of studying by myself and got a 29O (9PS/9VR/11BS). A couple weeks before the test, I took 2 Kaplan tests (I don't remember which ones) and got a 24 and a 27.
My Kaplan scores didn't exactly give me a good feeling about my upcoming MCAT, so I signed up for TPR class that would start a week before my Jan MCAT. As part of my study plan, I took a mock test every 1-2 weeks, and then one test every other day for the week of my actual MCAT. My scores were...
TPR#1: 23 (6PS 7V 10BS) <--- TPR's 1st diagnostic (I took this test few days before my actual January test)
TPR#2: 20 (5 6 9) <--- 2 weeks after start of TPR course
TPR#3: 26 (7 10 9) <--- 2 weeks later
TPR#4: 23 (6 8 9) <--- 1 week later
AAMC5: 29 (10 10 9) <--- 4 weeks later
AAMC6: 29 (9 8 12) <--- 1 week later
TPR#5: 27 (7 7 13) <--- 2 weeks later
AAMC7: 32 (10 11 11) <--- 3 weeks later
AAMC8: 29 (9 10 10) <--- 2 days later
AAMC9: 31 (10 9 12) <--- next day
AAMC10: 31 (10 10 11) <--- 2 days later
Actual MCAT 2 days later... 33O (11/9/13).
My opinion is that TPR tests aren't really good predictors, but they are good practice. After I walked out of my May MCAT, I thought the PS section felt about the same as practice AAMCs, verbal was longer and harder, and BS was WAY harder. I didn't expect to get anything more than a 30.
As it turns out, AAMC scores are pretty good predictors, and the curve on the actual MCAT can be really generous. Never in my dreams did I think I was going to get the score that I did. So, don't give up hope people!