About halfway through right now, and really enjoying it, quite a few chuckles as well, in typical Stross style (ie you have to know random facts to get some of the jokes). My favourite line so far is about a civilisation running a gift economy, which uses small spheres of plutonium as coins. The point being that any attempt at hoarding will result in the the plutonium going critical.
@ghostly So far all of the characters are robots/androids in the same style as Saturn's Children.
SPOILERS FOR SATURNS' CHILDREN BELOW
There are some resurrected humans knocking about the galaxy, known as the 'Fragile', although, true to their name "they have gone extinct at least three times".