Throughly enjoyed this book. Generally written from an informed physiological viewpoint, the guy knows his stuff, has great ideas for working within this genre and sounds like a superb vocal coach, hope he does a workshop near me someday. All the exercises are great and very refreshingly popular!
The only bit I didn't get was the use of old terminology regarding registers / voice (e.g. head, chest, falsetto), this lead to some misunderstandings and having to reread things and decipher.
He seems not to want to add any new terminology to an already overcrowded area, which is fair enough. Personally I felt that he confused things further by trying to mix the idea of a high / low register with head voice / chest voice. Terms such as Head and Chest make no sense to me and I feel they should be avoided by singing teachers.