The book is a good primer for LDR, D/s relationships. Almost everything in here I've incorporated into my own, as a Dom, and since I am a writer too, I also have a critical eye on what could have been included to make it a stronger book. My suggestion is that this book should have included not only the "how" and "what," but the "why."
"Why" does a submissive gain something from doing one of these tasks? Why does the Dom? What is the net benefit of it? There is a lot to be spoken about there and this book assumes the reader is aware of those drivers. It could have been a much more powerful book had the power exchange been explored more, and the needs and wants for the dynamic been covered.
Overall though, it sure as hell beats most D/s primer books, in that it was focused on a niche (LDR), and also that it provided specific examples of what to do, which is better than most I've read. It even gave me a dozen or so ideas, specifically in the "in-person" section.