He doesn't mince words, in fact he is applauded by others for his consise wording. He goes through every tone over every chord's significance, he gives you every chord in tons of inversions and makes you create your own chords. It's basically the price of two lessons, if you think about it, but it covers a lot more than just two lessons could cover.
Diagrams are just a small part of it. And I can describe the greek modes here in less than 15 words while still presenting information many people do not know. Arranged from lightest to darkest: lydian, ionian, mixolydian, dorian, aeolian, phryggian, and locrian. But he covers much more than that, including diminished half-whole and whole-half tone scales and of course melodic and harmonic minor.
I think it is great and I am learning from it because I am highly motivated to practice every day. It doesn't really teach technique, it is just a method book. But like I said, my friend who attended Musician's Institute as a kid said that this is by far his favorite method book. Learning from multiple sources is always good of course, and I learn from many different things constantly, my practices look like three practices hodgepodged together :) Another great book for guitarists who are already somewhat good (and can read notation) is The Advancing Guitarist. So that's my two cents :)
