I am currently reading the book. However, I can already say that the material is very well presented and is quite useful. While the subject of guitar playing may seem to be at great odds to the subject of martial arts; the concept of muscle memory is not. I have trained for over 25 years in serious martial arts, the principles outlined in this book regarding relaxation/slow movement to program muscles is very effective. I would rate this book a must have for any serious student of guitar.