I have two very big problems with this book:
1. Every single woman in this book is a victim of some kind of abuse and none of them are important except as motivation for the male characters.
2. The author has included a completely gratuitous rape. It is used as a minor event and does literally nothing to advance the plot. He seems to think that using rape for shock value is an acceptable thing to do.
More minor quibbles are that the big reveal is clunky and the method a bit uninspired, and the "mystery" of who is going around burning books was pretty obvious.
That said, I really do recommend reading this book. It was well-written (aside from the problems I had with it) and despite having already guessed who the arsonist was, my first time through the more I read the more I got drawn into it. By the end I couldn't put it down. The relationships between the characters were done very well. They are all three-dimensional. Fermin, in particular, is a delight. The book has a lot of memorable quotes and the author has some very amusing turns of phrase. It is definitely worth reading.
My problems with the book didn't really start bothering me until I read it a second time. While I still enjoyed the book, I was left with a vague feeling of disappointment.