Muay is absolutely brilliant. It provides an excellent insight in the techniques of the Thai martial arts. I doubt very much that a student of Muay Thai would be exposed to the wide array of techniques, principles, explanations and background knowledge that is contained in this book in many western Muay Thai gyms. Clearly a lot of research and experience has gone into preparing and writing it. From what I've seen, this is the only book of its kind on the market and is an absolute treasure trove of technical information on the subject. For anyone who trains in Muay Thai, or has a foundation in it, the contents of this book, if trained hard, would take them to a very high level, especially from a non sporting perspective, in the context of self protection and learning the art, and not simply the ring aspect which seems to be most prevalent.
In addition to anyone who is a Muay Thai practitioner/enthusiast I feel Muay would greatly benefit practitioners of Kali and Silat. From my own research and observations, I've found quite a bit of overlap between the techniques in the Thai martial arts and those in Kali and Silat. In fact, I would even include Burmese Bando, e.g. all the arts mentioned have a fair amout of limb destructions in their repertoire, and there seems to be some common resemblance between the techniques as well.
Master Lee's book has proved absolutely invaluable to me and provided me with an encyclopedia of techniques and knowledge, as well as an excellent platform to further research and investigate Muay Boran and Lerdrit. I have highly recommmended Muay to friends and hope to purchase further copies of this fantastic book.