I've read the three published books of the Lightbringer quartet, and I started this to tide me over till the fourth book comes out, frankly I was expecting less; an earlier book, a less experienced author, and at first I thought that's what I was getting. The beginning is a little slow, but it picks up speed quick. 
 Wow. Brent Weeks, I wish your series had more like 10 books apiece. I can hardly get enough of your characters. The plot twists are intricate, well thought out, and tie up nicely. Weeks breaks his series up in such a way to leave you wanting more, but not in a way that makes you feel like he deliberately stopped the book in an "exciting place" just to have a cliffhanger. 
 Azoth/Kylar is a little whiny at times, but that's about my only complaint. This book is a lot darker than any of the Lightbringer books for sure. (dark and light...haha...) Seriously though, Weeks certainly makes you consider the difficulties of living in the slums, and just how bad life is for some. 
 A lot more adult themes in this book, not counting the language or sexual innuendo. As well as some thought provoking speculation on theology. It is a book I would hesitate to recommend because of the content. 
 That said, I'm really looking forward to the rest of the series.