Many of us learned to improvise by running scales and modes, and then applying them to different chords in jazz progressions. The problem with that approach is that many of our solos sound like scale exercises instead of improvisation. Meanwhile, instead of learning the fretboard, we learned patterns. Now all of that may get you by, but you will always feel limited.
The difference between this book and so many of the others is the triad approach: learning the basic chords and extending them musically in your solos. Study this material and your solos will sound more like jazz and less like a finger exercise. Learning the fretboard is a natural byproduct of this study.
This book is not for beginners, but most intermediate players will be able to jump in and learn right away. Highly recommended.