I found this novel entertaining and challenging. I was surprised by the depth of this book; Meyer questions what it is to be human. This seems to be an increasingly common theme among novels, especially in fantasy and science fiction, but Meyer has an original take on it here.
Earth has been taken over by 'souls' and humans have almost been wiped out, being used as hosts for the 'souls'. But Meyer explores what happens what part of the human host remains. She changes our perceptions of aliens and of our own behaviour, particularly in a colony-type setting.
I found this really thought provoking and very moving. Though this is science fiction above all else, there is still the swoon-rendering romance we've come to expect from Meyer. We become so attached to the characters in here that it becomes quite heartbreaking at times.
If you're a Meyer sceptic, I would suggest reading this. She writes with poise and sincerity, and there isn't a vampire in sight.