ETA: Finished audiobook, and loved it. Excellent use of dual narration. Each narrator captures the quirks, humor, and personalities of his/her POV character. Great audio experience. 
 Update 12/20/2014: Re-reading via audiobook. 
 Review to follow, but here's the one-word synopsis: Wow. 
 Read this book! 
 ETA: My full review is now up at http://bookshelffantasies.com/2013/05....