Instruct: Classify Amazon reviews into positive or negative sentiment
Query: impossible to casually peruse, but invaluable to the serious

This text has been and still is tremendously illuminating to me. Though I have read it as casual reading a couple times, I have found it most useful when digested a concept at a time. The explanations while thick are neccessarily so. Professor Cheng has throughly described each motion and it's application. A very complex task indeed. Each time I work out I pick a section of the book and try to refine that portion of the form. Each time I am amazed by Cheng Tzu's ability to turn a movement I have made thousands of times into something new and amazing. I highly recommend this text to any serious student of Tai Chi. I also warn any novice student that they should start with one of Cheng Man Ching's more elementary texts. This one is difficult to comprehend if aren't already familiar with Cheng Man Ching's style of Tai Chi.