I read Dr Chang's book and found it interesting, but also had a few very specific criticisms.
First off, writing style and mechanics: This book read like a series of compiled message board posts, as opposed to a coherent book. It is repetitive and/or rambling in all the wrong places but fails to flesh out some of the important details in places and really feels like it is in drastic need of an editor, or at least someone to read it with the red pen in hand. I admire that it is self-published in many respects, but it could certainly be improved by a careful, thoughtful overhaul. If it were up to me, the book would begin by introducing a standard practice routine for a day, then it would break each aspect of that down and analyze each facet, then finally conclude by reexamining that day's practice, in light of what was discussed above. I think that with good editing, the book could be about 1/3 the length.
Next, lack of diagrams: it would really help to have the passages of music referenced in the book printed in line with the text, so that the reader can understand what is being discussed. The whole piece doesn't need to be there, just the specific bars.
Next, overdependence on acronyms: A good book can get by without using acronyms much at all, and is much easier to read. Some are inevitable, but any time that one feels they are repeating a word too much, their first instinct should be to rephrase, second to get a thesaurus, and finally to use a standard acronym. Making up acronyms should be avoided, as it is confusing at best.
A side point, semi-medical advice: Dr Chang is not a physician, and should not speak on medical matters as though he is. Much of his section on health is simply incorrect.
Next, the anti-Hanon bent: fine, you don't like Hanon, and there certainly are limitations to it. But, you espouse frequent playing of scales and arpeggios, which are also known as exercises 39-43 of Hanon. I'm confused. We can argue endlessly about the value or lack thereof in doing exercises, but we should be honest about it.
Furthermore, the rigidity of the method: the Chang means of practicing is but one of many approaches, and likely to work for certain people, but not everyone. There are many ways of learning any task, and while some are probably better than others in general, they may not work equally well across the board because of different learning styles. Additionally, different styles of music may call for different practice routines--the obvious difference would be classical vs jazz, but more subtle differences could be based on your performance goals--are you playing for personal pleasure, as background music in a bar, or at a concert hall? Each of them are vastly different standards, and if you practice in the same way you won't be as efficient. Further examples: for me, it is most efficient to practice with separate hands only until I get the basic gist of a passage, and then to combine, especially for pieces with heavy involvement of both hands or heavy syncopations. For really tough passages, I end up spending a lot of time on the more difficult hand, but I try to get my hands together relatively quickly. A great example of where this helps me is in passages with the melody being carried partly by both hands, or passages where the two hands run into each other--playing them separately is actually injurious.
On a related note, linear learning, math, etc: There is a lot of discussion about how quickly one can learn a piece, how many minutes it should take to do a certain task, etc, and really, this is an oversimplification at best. Some things come more quickly than expected, others take longer, and applying a rigid equation to learning speed is in general counterproductive. Sometimes we hit not just a "speed wall," but a big fat learning wall. Sometimes we make rapid progress overnight, and other times we plateau.
Final criticism for now: self praise and testimonials. I'm pretty sure the "review" of the book was written by Dr Chang, and that's just something you're not supposed to do. You're supposed to pay someone from a minor newspaper or magazine to write an effusive blurb.

Ok, I've criticized enough. I actually agree with the majority of the compliments to the book earlier in the thread, and overall I think it is a noble effort to improve people's piano practice time.