I got a 5 and an 800 in it. I took it as a sophomore and it was my first AP. I used Barron's which I really like if you want a very high score and also want to use it to complement your high school class. PR
is also really well written though. Nice thematic review approach. Honestly, for most ppl PR
will be more than enough but if you are a masochist, go for Barron's. If you don't get a 5 after really studying Barron's, you have a problem.
Most important though in WH is the big picture. Details are helpful but the big picture is what gets you through the test.