I'd actually like to give this one 3.5 stars, at least until I read the sequel. It was a decent enough book, a compelling read, but it did have a few problems; it felt like a good novella that had been padded to make a fat novel and subsequently suffered for it.
Certain of the more SF aspects of the plot never really made sense; they felt very much tacked on, almost workshop-style ("I don't think this'll sell as scifi, Bob...why dontcha add some aliens or something?") The core story is quite a good one, though, and I will pick up the sequel to find out if Baxter manages to coax a convincing extra rabbit out of this one.