Very useful for understanding Yang
In order to make my own practice of the dynamics more meaningful, I study The Essence and Applications of Taijiquan. But that book has only static pictures of Yang Chengfu performing the dynamics. So I use Fu's book to more thoroughly understand what Yang is trying to teach. This book is very good in this way with multiple diagrams for each dynamic. You could easily learn a better long Yang form with this book alone than you could from many teachers.

Great reference book!
I highly recommend this book to serious practitioners. I use it diligently. Even though it's a publicized 'health' version of the Yang style form, the book serves as a repeated reference for years to come.

NOTE - Must be used in conjunction with lessons!

It's a thick read, complex, and detailed, so go at it with the mindset of looking up the posture you're working on, reading up on that posture, and getting maybe one or two things out of the text. Practice for a few months, go back and reread the same posture and you'll pick up a couple more things. Wash, rinse, repeat. This is what makes it an incredible book with great depth.

The negatives of this book are that it could use more photos of in between movements, more footwork diagrams, and definitely application, but there's a companion book by the same author covering that information - The Essence and Applications of Taijiquan

RECOMMENDED - a good guide for the intermediate practitioner
This book is a translation of Fu's step-by-step description of the Yang style Tai Chi form as it was taught to him. Each technique is described in detail, along with illustrations and notes for the student. The ONLY problem I have with this book is that instead of presenting the material in a linear fashion as Fu's original, the reader is required to flip back and forth when referring to material already presented (so I docked one star for this cheapness/ laziness). There is also a brief overview of push hands, and what I believe to be a more faithful translation of the Tai Chi Classics - more closely capturing the poetic beauty of the original Chinese.

the best
That's the best book of Yang Style Taijiquan i've ever read. Much better than the others (including the book of Yang Chenfu, and Zhen Manqing and Yang Zhenduo's books). Its incredibily clear and detailed. But that's not a beginner's book, its for those advanced students who already knows the traditional yang long form.

Amazing
Pretty much what you are looking for in a Yang family style book. It will not teach you Taijiquan, find a teacher for that. It will help you look upon what you are doing better and with a wider eye. It is very interesting, and if you are asking questions about the forms and stuff you are learning, this will answer them.

A definite must for any Yang family Taijiquan lookers ;) Very nice, Very much worth the money, yet it should be worth more, in my opinion.