The only disappointment I had in this excellent book was realizing partway through that it was not actually a true story. That being said, the forums on the book's website, http://theshackbook.com, point out that there are basises (is that a word?) on truth throughout the book. Certainly the conversations between God and the main character make sense and fall in line with biblical truths that I understand so far, but I have to be careful to not consider God as being just like the personified character(s) in the book. Though, as He says in the story, any attempt to personify God is going to fall vastly short of the real thing.
The story was incredibly emotional and while everyone, including myself, can find ways to relate to the characters, I still pray I never have to go through anywhere near that amount of pain in my life. Yikes! It definitely made me want to go hug my girls and tell them I loved them!
I had expected a slightly different ending, though to avoid giving the story completely away, I'll keep it to myself. :) The ending was still excellent, even if it left me wanting more (which as I've said before, I assume is just another indicator of a good book).