Hmmm. I mostly enjoyed this! A lot of reviewers have said so at this point, but you'll like it a lot more if you don't go into this expecting horror. This book is a lot more of a literary/mystery/thriller situation. A few sections were difficult to get through, and I actually think rather than trying to save some of the final revelations for the end, I would have gotten through them more easily if the book went ahead and revealed the connections between the characters from the start. 
The very end really let me down. The author has the MC who is closest to his own background essentially say "this is the theme of my story" and another character respond "ouch, that's hard to hear," which, after building the theme throughout the book, felt very heavy-handed and out of place.