The book has some very good introduction chapters, detailing the history and background of Krav Maga. It points out the difference between KM and martial arts, and why KM is so effective in real life situations. Very well written, and clearly the authors have put a lot of thought into defining things, like the difference between a principle and a technique.
The instructions are pretty straightforward and photos are mostly good, though slightly lacking in print contrast. The introduction contains a short terminology list, however the instructions sometimes use words not obvious to the beginner, such as "telegraphing" (the act of revealing your intended attack or move too early). As far as I could tell most techniques were correctly described and explained properly - no wonder considering the source of information is Darren Levine.
The book wisely states several times that a book can't replace actual physical training with an instructor, and recommend that you practice the instructions in the book with a friend, first slowly then faster and harder. My words exactly, but the book can be great for referencing the philosophy behind KM and the moves up to a certain level.
Having personally trained Krav Maga for a relatively short period of time at the Krav Maga Center in Denmark, it's hats off to a system that's not only very effective but so amazingly easy to remember. Krav Maga is based on the body's own initial and natural responses, and moves are based on principles rather making up a defense for each possible attack you could think of. Reading through the first two instruction chapters (yellow and orange belt) I realized I remembered 99% of all the excercises from my training.
I recommend the book for beginners to medium level, while the introduction chapters are probably of interest to everybody who trains Krav Maga.