It's the far future. Earth is a distant memory... most people don't even live on planets anymore, but rather small habitats linked by wormhole gates. And death's difficult to come by, because you can back yourself up as easily as taking a shower. If you want, you can change your body-plan or gender while you're at it. But there are still wars, and in the wake of one, many people have chosen to wipe their memories and start fresh. Some of these people, including Robin, an ex-spy who may have a mission so secret even he isn't aware of it, are recruited into what seems like an innocent three-year experiment, to examine how the society of the 20th century worked, by establishing a community following similar rules as they had to live under. No choosing your body. No instant repair. No ability to leave early if you don't like it. And a lot of expectations for how you behave. And Robin's worried the experiment may be run by war criminals with a nefarious agenda.
I've read this book at least four times now. That alone should tell you that I really enjoy it. In fact, it may be my favorite of Stross' novels that I've read (unfortunately, I believe it was also one of his lowest selling, which derailed chances of a follow-up or something in the same universe).
It's got a nice mix of different things I love in SF, things that don't always go together... wildly imaginative (but still somehow feeling plausible) speculation about the future and what kinds of technologies we'll have and how they'll shape our lives, as well as an engaging, easily relatable story. It's at time funny, fascinating, chilling, and making important points in a rather subtle way.
Of particular note is the look at how things we consider natural are often mostly matters of social comformity that can be manipulated from the top down, and how hard it is to fight it from the bottom when everyone else has bought in. I also really loved the brief glimpses we get at the censorship wars and wanted more about that, somehow, though I suppose it's hard to tell a satisfying complete story about a war where the people fighting it aren't allowed to remember why.
The book does have a few bumps, moments where either something felt obvious to me, the reader (even on the first read) but characters remained ignorant, or where interactions just felt slightly off... and, for that matter, there were times where the author handwaves reasons for the enemies to be defeatable. At least several times in the book, I was thinking, "Okay, but, really, if they wanted to, they could monitor that," and the reason given for why they wouldn't I just had to accept even though I didn't entirely buy into it.
There's also some treatment of gender that sometimes felt, at first glance, a little broad, even near the point of stereotypical. I do think it's a lot more nuanced than it looks, but the fact that it's a society where gender roles are being deliberately enforced and also that characters are sometimes in bodies specifically what they wouldn't choose (and so, the more unpleasant aspects would certainly weigh more heavily on their minds), but the first few reads I counted it as more of a (very slight) negative than I do now.
Still, I enjoy rereading this book every once in a while. I also think it could make a great TV or Netflix series. That's not to say books need that to be considered good, but part of the fun I get out of rereading in general is, since I don't have to spend as much effort undertanding what's going on, I can use some of the spare thinkspace to imagine how it might be adapted, if it were going to happen. I enjoy it. But I reread a lot of books, and while I might play this game with many of them, I think this could be one of the easier ones to do that way. Even though it's got big, complex SF ideas in there, most of it could be done on a budget of any non-genre show. That seems like a recipe for success (although, ignorant people would probably call it a Wayward Pines knock off or something. :P).