The major premise of the book is that adding small amounts of the right kind of carbohydrates to your diet is superior to a strict ketogenic diet. I admit this was true for me; after a year on the keto diet, this change brought some significant health benefits. I slept better, had fewer, ahem, bathroom issues, and was finally able to shed those last couple of inches off my waist. Also, I just plain enjoy eating potatoes and rice!
BUT: I was not happy with the basis of the amount of carbohydrates they recommend: they reviewed the carbohydrate intakes of several large animal & primate species, accounting for conversion of resistant starches to fatty acids in the colon (a rather brilliant observation), then doubled this arbitrarily for some completely unsupported reasons. That is too much for me, so I had to experiment a bit to find the optimal level. I also think it's important not to go straight to this moderate carb diet, but to attempt this only after "fixing" your broken metabolism with the ketogenic diet. After years of following USDA guidelines and eating mostly carbohydrates and sugar, your ability to metabolize fats is atrophied and needs the equivalent of a dietary boot camp to restart. Also, their recommendation to go low fat for dieting is exactly wrong: you need to INCREASE fat intake, not decrease it to lose weight! That may sound counterintuitive, but if low fat (meaning high carbohydrate) diets were the way to go, why do they have a 96% failure rate?
They also provide a useful summary of micronutrients and a pointer to recommended supplements, but if you followed all of them you'd be eating more supplements than actual food. Other authors do a much better job at identifying the most critical and common deficiencies, and the supplements that give you the most bang for the buck.
So overall, a couple of excellent dietary points that make it worthwhile to buy the book - but beware of the other 80% of it which is a bit misguided, or just a compilation of recycled material from the Internet.