Fairly standard fun generic hyper futuristic universe where death is no longer a problem, and you can get downloaded into bodies of whatever gender, shape, type you want. Interesting twist is that characters have had their mind wiped to deal with the longevity of their lives, to deal with lost loved ones, or heinous crimes commited.

Briefly of covers some of the problems relating to gender discrimination and gender dysphoria and then kind of decides that it wants to be a standard sci-fi action book (which is fun, but I've read a few of those now) by forcing the characters into a 1950's-ish (mostly ish) society, and swapping round their genders.

Sort of got tired of it half way though, but this seems to happen a lot with Stross books, then it picked up again towards the end.