This is a weird book; having finished it, I'm kinda scratching my head and going "Erh?"
It starts out with a future a couple of hundred years hence mainly shaped by the unintended but believable consequences of a technology the likes of which we might well see. Although this isn't what the book is really about, it is the sort of topic that science fiction is supposed to speculate about. The story then introduces another believable technological development, and starts along a story that seems to be fairly interesting and making some sense, and then we run into a plot twist based on something I can't believe in, but that I am willing to read about, although slightly disappointed. And then another plot twist comes along that casts the whole story in a different, confusing light.
Ultimately, I think there's supposed to be a significant point about life and death and the nature of reality here, but it's not very compelling to me. In the end, it's an odd but engaging story that ends up somewhere that's just plain odd. I find it hard to rate, because I rather enjoyed the story but I don't like ending up confused. I guess I'll go with 7 out of 10.