How realistic are Princeton Review tests?

Test Preparation
1

I have SAT subject test for (M2,Phy and Chem) on 2nd May. I am easily getting 800 in all the three subjects on Princeton Review tests. I am a bit skeptical about this since the score conversion table given in PR tests looks very lenient to me. That is you will get 800 in following cases:

Leaving 10-15 (Raw score 60-65) questions in Physics = 800
Leaving 6-7 (Raw score 78-79) questions in Chem. = 800
Leaving 6-7 (Raw score 43-44) in Math 2 = 800

Please tell me if this curve reflects the same as that of the real test.
PS: I am giving subject test for the first time and have no idea about any previous curve
Thanks.

2

They are correct. And some of the questions in PR Math Level 2 appeared in the real test! (With dif numbers)