I've enjoyed this series as a whole but I think this was a particularly strong entry.
There were a few different plotlines going on, which was interesting. The experiment with POV worked, I thought, although traditionally I think when you have multiple POV it's usually somewhat evenly divided, but whatever.
What really made this book 5 stars was the treatment of Claire's death. Could not have been handled better. I cried, enough though I figured she couldn't stay dead. Important people tend not to, in Morganville, and she is the main character, after all.
I'm fairly certain that Amelie will not actually die, although the idea of Morganville under Oliver's leadership (particularly if he's just lost Amelie) is both interesting and terrifying.