Who has ever used??

[mrkpower]

Hi all, just wondering who has ever used this book, is it helpful? Need your thoughts please!
Thanks!!

Fretboard Theory by Desi Serna http://www.amazon.com/Fretboard-Theo.../dp/B000H21RVC

[Big E]

I have looked at it and fell it is a great resource. Yes that information is available online for free, but having it all together in one book and well laid out is a bonus.