I first bought this book before law school but thought I would comment on this book now after going through a year and a half of law school and taking several exams.
Overall, the book does a good job lining out several formulas for successful exam writing. It provides useful examples to the reader that will probably result in better exam scores for those who understand what is expected of them on their first actual law school exams. However, past those first exams, readers will gain little from the content of this book. Like other readers and fellow "lawschoolers", it is my experience that at least half of your professors will discuss with you what they expect on their exams, and a few may even choose to outline the "sacred" IRAC method in class or on demand. Most students pick up what is expected of them from those teachings or by searching out past exams. Even reading case law may help students understand how they should answer an issue by demonstrating how learned judges apply their own ideas and argument to legal issues.
Most law students know after the first few trials what method works. After that, it is all about your work ethic and that thing located between your ears. The hardest working students are the ones who get the best grades, usually by preparing better than most others. Believe it or not, the problem of knowing how to write a law school exam disappears very quickly for those hardworking enough to search out the resources available to have meaningful, practical repetitions. Reading a book isn't likely to make you a better exam writer. You'll have to dig your hands into the clay before you can master the potter's wheel.
Save your time and money.