I was hoping to blow through this book in a couple of weeks. After a couple of pages I realized it was for the 'serious' guitar player - willing to invest time and effort in a long term effort to grow by listening critically and making changes to the way we approach, practice, and play the guitar.
While going through the book I felt as though the author was right there in the room with me for each exercise, keeping me on track with comments on how to approach each lesson and what to listen for. I liked the section on how to practice, and the example to chart your progress.
Look at the table of contents. Every one of the exercises will improve your technique, even if you already know the basic concepts. Each example starts at square one and explains how to break out of old habits and patterns to get the most out of what each 'unit' has to offer.
Read the other reviews - they're probably going to say the same thing: this book will challenge you, regardless of your familiarity with the guitar and your technical abilities.
Pros: You will learn to break away from playing every note in a scale to create something memorable. You'll break the habit of playing consecutive scale tones, learn new approaches to make your playing more musical, and feel comfortable playing new things anywhere on the guitar.
Cons: If you follow the author's advice, you'll have to slow down, listen to what you're doing, and make corrections on the fly. In the end, music is about listening, after all. If you're more interested in how you look while holding a guitar, or how fast you can play the same old patterns, you won't enjoy the effort required to complete these tutorials.
After years of playing, I was surprised to see the difference between what I thought I sounded like, and what was coming out when I did the exercises in the book.
If you're ready to invest the time, this book will take you and your guitar to the next level. This one will separate students of guitar from every one else.