Loved it. It's catalogued as SF in the library but I think it's one of those books that doesn't easily fit into one genre. Very much a look at decisions and how they affect not only one person but ripples in a pond outwards from that. An emotional ride, with rich characters. The story stayed with me after I'd finished reading and will do so for some time. 
 This is the 2nd Jo Walton book I've read and she's now on my auto read list.