It's not hard to categorize this book, even for all the little quirks that creep in that is not all that standard for our UF craze. 
 You named it: Vampires. Werewolves. Love-interest between the two. Oh, my. 
 Don't get me wrong, it's good for what it is, a fast-paced stereotype-laden action romp that tickles most of the fancies even as it fails to nourish. In other words, it's fast food. 
 Some of the dialogue reads out of a cliche manual, but the energy is bright and there seems to be real love from the author for the world he's building. It's right out of Vampire Masquerade, only the names have changed and the number of houses decreased, but that's fine, too. We're here to focus on the Underworld chosen one syndrome... and her name is Bethany. :) 
 BUT, let me tell you what it does right: Pace, high-energy characters, willingness to introduce some wacky SF elements, and the obvious build-up to some really Big Happenings later. 
 Wanna change the world, one torn throat at a time? This is probably your book. :) 
 I like it well enough, but I suspect that I like it more because I listened to the equally high-energy narration within the audiobook. I also suspect that any number of editing sins can be swept under the rug this way, too. :) 
 No matter. I enjoyed it. 
 I'll probably enjoy tearing through the rest of the series, too, because it's all a very light read that doesn't much challenge us. We can just roll with the action and the spunky (aggressive) heroine as she discovers just how much damage she can do to the world around her. :)