Yes, I'm a twilight fan, but I wasn't really sure what to think when Stephenie announced the release of this novella. Is she just cashing in on her wild success? Will it actually add anything to the story? Will the writing be any good or will it be rubbish? Well, I read it this afternoon (didn't take too long, it's quite short) and if you're interested it's available online here for a short time. I read it online, because I wasn't sure I wanted to own it. Now that I've finished it, I'm pretty sure I will want to buy it, if for nothing but to put its pretty matching cover up on my bookshelf with Stephenie's other books. :D
So...I think it does add something to the story. But not much. My biggest problem with this book is that it's a vampire book. "But aren't all Twilight books vampire books?" you ask? Well, not really. The Twilight series doesn't much go into the gory aspects of non-vegetarian vampires, but Bree does. There were way too many descriptions of Bree gorging on human blood without feeling a bit of remorse. Yuck.
Other than that, the story is short and boring and the romance is practically non-existent. I never felt like I really got invested in Bree as a character (or Diego for that matter). There's one great character named Fred that's introduced, and there are some worthwhile moments at the end when the Cullens show up. There's a short mental communication between Bree and Edward that I particularly thought added to the story. Other than that, not much to say. We all know how it ends.
If you're a Twilight fan, I recommend reading it online, unless you're like me and have an obsession with owning completed sets. :D