Kim Stanley Robinson is one of the writers I talk about when I'm trying to explain the particular value of SF to sceptics. Along with people like Ken McLeod, Robinson is writing books about the way things might be if we got our act together. A lot of SF is intensely political; some of the really bad SF is reactionary as hell, power trip fantasies of the ubermensch running things the way they ought to be run. Or as they like to call themselves, libertarians. There isn't much of a left view in SF, and KSR is probably the most prominent figurehead for it.
That viewpoint - a preoccupation with how communities can live to their best advantage rather than the whims of an elite - informs all of his work, and I often wish it could be more influential than it appears to be. But those preoccupations can get in the way of the story; I could never finish the Mars Trilogy because the characters never came to life for me. There was something very uninvolving about them. KSR is one of those writers I admire but can't always read all the way through (I've read less than half of his published output despite my constant recommendations of the "good" ones).
2312 at first struck me as being a bit like John Varley's The Ophiuchi Hotline, which is as much about showing us as much of the solar system as possible as it is about the ostensible story. Varley had a very well worked out notion of a colonised solar system and wrote a load of stories set in it; although the Gaea trilogy is probably still his most satisfying work, the "Eight Worlds" stories are a more impressive feat of sustained storytelling. KSR has packed his own vision of a populated solar system into a single book, but it comes at the expense of story and character. After a while I started to think that the story he really wanted to tell was the story of what had to be done to make the solar system somehow habitable for his characters; there are constant interludes into the action where asteroids or moons or spaceships get pages of explanation. And those pages are somehow better reading than the chapters about the characters.
I found myself wondering what I was missing. Would Swan make more sense as a character if I'd read Proust? Would Inspector Genette have made more of a connection for me if I had more than a passing familiarity with the plot of Les Miserables? I still don't know. The plot places the three main characters wherever they need to be in order to see the big action set pieces, but it's never clear why they just happen to be in the right place at the wrong time, as though by chance. There's the constant suggestion of a larger scheme around them, but they never feel integrated into the benign conspiracy which is driving the action. In part that's because KSR is using the age-old suspense driver of not letting us see what's going on until it happens, but it means in practice that nothing makes much sense until it happens, and it doesn't necessarily make much sense afterwards either.
In short, this is not a particularly good book, just considered as a book. If you consider it as a bag of ideas, it's marvellous; KSR covers dozens of plausible notions of terraforming and governance for the wider solar system, and throws in for free a profoundly gloomy picture of an Earth trampled by global warming and still stubbornly repeating the same mistakes which make today such a discouraging spectacle for anyone interested in universal justice and fairness.
There's an age old Irish answer to a request for directions which runs "Well, if I was going there, I wouldn't set out from here." If you haven't already started trying to read KSR, I wouldn't start here. Start with Antarctica, which has the advantage of a straightforward plot and time frame and some pretty good characters. Or with The Years of Rice and Salt, which has a fantastic opening premise and a cleverer way of putting the characters into the middle of everything which happens for hundreds of years after the Black Death depopulates Europe completely. If you like those, you're ready for 2312, which is well worth your time as long as you remember that this one is all about the ideas.