A friend of mine and I both had copies of the Barron's book, and we decided to sit down on a Saturday and take a mock full-length test together. We did the same test out of each book.
When we scored our tests, we didn't do very well. However, once we started checking what we missed, we realized that there were answers in the key that were just blatantly wrong.
What's even more absurd - our answer keys were different! Some of the answers in my answer key were completely different from his. The answers weren't necessarily changed to correct answers, either. We figured that one of our books was a revision of the other, but couldn't find evidence of this anywhere in the book.
The Barron's book is useful for its advice on PAT methods, and for the PAT practice since its examples are fairly difficult (although I wouldn't trust the answers given). It is also helpful for its application advice, and for some of its other test-taking advice.
Other than that, in my opinion, the book is crap. Don't waste your time with it. The biology section simply goes into WAY too much depth. Focus on everything Kaplan's got to offer and you'll be spending your time much more efficiently.
