I bought and read the previous 3 books in the saga and thoroughly enjoyed them - I literally could not put them down!
However, I found the 4th and final book very slow. The first 500 pages have no action and I was left wondering where the story was leading. I did enjoy the change in narration in the middle of the book but I was disappointed with the overall lack of direction.
The twists in the book were not what I was expecting, but I this did not leave me excited or wanting more - I was confused and actually quite upset at how Stephenie tied up the story. The ending was not what I expected (not in a good way). From talking to friends who have not read the final book, I think that they will be disappointed too. I don't want to say too much about the ending...
Buy the book if you have read the others in the saga, you need to find out what the ending is, but I feel that this was a let down and had potential to end an otherwise brilliant collection of books.