This book could be useful for anyone who wants to build his or her vocabulary. The book includes the obligatory vocabulary list (2300 words) but this can safely be ignored. The real value is found in the first half of the book. There is an extensive section on prefixes, suffixes and roots, followed by lists of "the most frequent SAT words." These are lists of SAT words that all have roughly the same meaning followed by another list of words that all have roughly the opposite meaning. For example: The first pair of lists are words that mean "to praise" and words that mean "to belittle." Rather than learn these approximately 280 words in alphabetical order, you can learn words together that all have a similar meaning.
This is not a book you can pick up the day before the exam for an immediate difference. You will need to work on learning these words and roots for a month or more, so make sure you get started well before test time.