It is great book! A bit rough at the beginning, but get more smooth with time.
Lot of exercises are same as in yoga, but here focus is completely different. Main topic is our conscious of body, muscles and changing bad physical habits, where yoga is more about calming down, reduce stress and tension in body. At the end both do the same, but I found that not everybody is benefiting from yoga. That's probably because of just following instructions and not gaining conscious of body during practice.
I think that practice of this exercises can change life quality!