I've studied many of the contemplative traditions of the world-- Zen, two schools of Tibetan Buddhism, Taoism/chikung, and have dabbled in Sufi, Jewish, Hindu, and Christian mysticisms and have studied Shotokan karate and Aikido. I've studied religions of the world at Swarthmore College and at Naropa and have done my best to study with a great many amazing masters of a number of traditions. I'm an insatiable reader...
Having said that, this book really is the single best A-Z resource for understanding the tools and principles of energy cultivation and meditation out there.
This book is an excellent tool for those who seek truth. It has helped me and changed me. I keep it on my night stand.