Pearson! But Kaplan is good to check the overall depth of your knowledge... if you do ok with Kaplan (not just get lucky and guess right, but actually know the material) you should have no problem with the real thing... my Kaplan was 70-80, Pearson was 85-90, PCAT overall 95
P.S: I'm talking about bio, Chem, math...didn't study for reading at all...I think it's a waste of time because you either good at this or you are not...I guessed most of the reading questions and still got into 60s