A while back, for a previous edition of this book, I left a pretty scathing, one sentence review. As I prepare to try to get a perfect score on the exam, I realize that I am in need of practice exams (I exhausted everything else). I had about 10 tests left-over from my earlier ediiton of this book, but I decided that I ought to give the new edition a try. It's much better!

The tests themselves are very good when there aren't mistakes in the back of the book (explanation answers don't match listed answers, etc.), but these errors are sparsely distributed.

The math sections are sufficiently "tricky" and test reasoning abilities just as the real exam does. The content's about right, although as a previous reviewer mentioned, there are a few SAT Math Level 1 type questions in here so the content, if anything, is a little more advanced. But if you're out of CB tests, these are still really good.

The writing sections are pretty good, except for the fact that some questions are poorly worded/incorrect, but I'll excuse them because if you're making 12 tests, some errors are bound to happen.

The critical reading's a little weird. The passages are...about the same, although maybe written at a slightly lower level, but the questions sometimes have a hint of ambiguity that isn't there on the real exam or on the blue book tests. All in all, they're still pretty good, and it's good reading practice in general. The sentence completions, I've found, don't test as difficult vocabulary as the real thing, but the sentences are a little more difficult to decipher. Meh, it's okay though.

In any case, this is a good set of tests. No, it's not as good as CB material, but it's all I've left. It's not half bad.

My son got a perfect score after struggling with this book. I guess it means it is helpful.

I am a full-time tutor and have several of my students use this book. As with any test prep book not published by the College Board, there a couple of questionable questions. The answers and explanations sections are fair; I have not found a book that offers very good commentary on answer choices. The explanations still give a student the chance to work independently.
Some questions are modeled after the College Board book's while others are not.
Overall, Kaplan 12 is valuable, because it is most important for students to PRACTICE and think critically about their incorrect answers. Where are you going to find more practice?