Ironically, I think this is my favorite book of the series. It's more raw, less over the top dysfunctionally romantic, and provides a really nice insight into a newborn vampire. It also enriches Bella's story, I think - I loved the dovetailing of this story with Eclipse - and helps understand the terror the newbies inspired.
It's very short. I read it the same night I (finally) got in on reserve at the library.
Would love to see "The Long First Life of Bree Tanner" to give us more insight into her backstory.