I just finished reading the PR
one and when I took a practice test my score went up 50 points (650 to a 700), but now I'm starting to read the cliffnotes ones and it has more thorough information that the PR
doesnt have. Even though the Cliffnotes sometimes gets too specific, you can just skip those parts and save a lot of time. The cliffnotes has answers to questions on the SAT that the princeton cant.
Overall, the PR
WILL prepare you, but if you want 700-800 I would say study the Cliffnotes. Good Luck.