While this book contains references to many SF books of the 50's and 60's, what it mainly is, is an homage to the author Cordwainer Smith, who was really Paul Anthony Linebarger. Apparently, no other reviewers have mentioned this, yet I find it one of the most important things about this book. Smith/Linebarger wrote SF for only a few years, right around 1960, and no one since has written anything like his stuff. In this book, Stross manages to incorporate some of Smith's recurring themes, and tie them into his own recurring vision of a post-Singularity techno-human future, while also bringing in new takes on the old idea of generation ships. Some of the obvious references include one of our protagonist Robin's past lives as a "Linebarger Cat" and there are others that will be familiar to those of us who have read Smith. Those of you who haven't read Smith - well, this will be a fun read anyway, a fast-paced story of recovering from interstellar warfare with dubious psychological help. But you really should go back and read Cordwainer Smith. His few novels and many short stories are collected into less than half a dozen paperbacks; get them while you're at it.
Why, you say, should I read SF written before I was born? Because it's part of the history of the genre, and HISTORY IS IMPORTANT - that's the main point of the book!
The ideas include: what makes us human? Is it human shape? Is it being able to reproduce, creating other humans? Is it free will? Is there such a thing as free will? Stross does not concentrate on religion as much as Smith did, and Stross's ideas about it are a bit more simplistic, but he pays every bit as much attention to free will, and to being able to shape the environment one wants to live in. In Smith's books, the Instrumentality of Mankind had to decide whether to allow people to make mistakes again, and to allow them to live in environments which are not perfect, instead of protecting them (cf. "Alpha Ralpha Boulevard"); here, Stross plays with the idea of psychological conditioning to give people the lives they *should* want, and with erasing memories in order to control people. Smith's part-animal Underpeople had limitations on their reproduction, but some overlooked Underpeople started having thoughts of being their own owners and of raising their children free of the conditioning given servants; Stross has humans who have forgotten natural reproduction and are being co-erced into it in order to bring children up unaware of freedom.
There is more here - wordplay in the Asian-ish names of organizations and some people is another connection to Smith, for example, but there are also subtle bits of humor that seem to invoke everything from fantasies with too many elves and swords, to a person who seems to have become a unicorn My Little Pony. We even get some *really* old classics - "Never bring a knife to a gun fight," for example.
In short: it can be read and enjoyed as a decent, fast-paced thriller combining space war and some post-human body modification/back-yourself-up-on-computer cyberpunk, but it can be enjoyed even more as a way to connect those genres to some of the greatest science fiction of the 1950's and 1960's, the stuff that kept the genre from dying out as just a fad.