I really liked this book. It was a bit of a mind-f***, which was a good thing, I think.
The idea of parallel universes really confused me, and I'm still not sure how I feel about Viv. I want to think that our Cam's Viv was different, but I don't know if she was. I guess I'm going through the same struggle that Cam did.
Basically, this book was really interesting and engaging, and it's a pretty quick read. I'd suggest it to anyone who wants to read something that will confuse them, but make them think.