I studied with this professor in college so while somewhat biased, i think that makes this review that much more informed.
Let me start out by saying that Ed Deci is a genius in social behavior. The man is as intuitive and understanding of a therapist as I've seen, with an uncanny ability to cut through the "bubble-wrap" with which most of us insulate our lives. He understands people like Da Vinci understood...well everything. Moving forward, this is not an easy read. In fact, if it's the first thing you've ever read about the topic, you will likely be bored. I know a handful of people who couldn't get passed page 50. It is a very academic book and tough to stomach without a guide. If you are interested in the topic, though, this is about as comprehensive as it gets. Straight from the horses mouth, with cool examples and real world context. As part of our required reading, this served as an excellent supplement to Deci's teachings.
Definitely recommended for anyone studying causalities, motivation, social psych, I/O, or even religion. Also recommended for hiring managers and HR personnel.