If you have time to do both, then do both as it definately wont hurt you. But if you are limited in time, then I would figure out what type of problem you have trouble with the most. There are usually 3 sets of pure physics/chemistry problems not associated with passages. So, that comes out to roughly 18 questions, add a few more in for random questions in passage sets that arnt associated with the passage...and your probably looking at around 30 questions without passage reference. Of those 30, probably 65% are physics. Thats a lot of points right there if you dont do well on those. But then again, theres probably an equal amount or more of passage based problems.
Personally, I never used the Berkely review's physics book, but I have heard they are great. If they are anything like their Verbal Reasoning book, which I loved, then I would definately say go for it. But, I was studying for the exam, I used EK and Kraplan books and was able to score an 11 on the real exam.