This book certainly lives up to its subtitle. I wouldn't recommend this as an introduction (the author has another intro Ayurveda book published), and this certainly isn't a how to practice Ayurveda. Instead, it is a wide view on the history of Ayurveda and an exploration of its different parts.
Ninivaggi takes time to compare Ayurveda to modern science and medicine, as well as Buddhism, yoga, Chinese medicine, to name a few. He doesn't attempt to create a correlation between modern medicine and Ayurveda, but brings up parallels when they occur.
I enjoyed the wealth of knowledge in this book. This would be good as a supplement to other Ayurveda materials. The style of the writing is somewhat scholarly, which may turn some people off. Overall, I would say Ninivaggi explains Ayurveda in a matter-of-fact way.