I found this book a bit up and down at times. Many of the individual passages were great. Others, I didn't enjoy so much. But I think what troubled me about the book was the way the passages didn't always hang well together. I was looking for a thread linking all the stories. It was easy to discern in the beginning, but it petered out, until the very end. The last passage rescues the story nicely and without it the book would have been nowhere near as good.
While the subject matter is very worthy, this on its own is not enough for me to give it more than three stars. I did almost abandon it with only five chapters to go (I did enjoy the chapters in the beginning, but I experienced diminishing returns as I read), but I am glad I persevered, as it is the last chapter that redeems the story.