I just finished the book this evening and can still strongly recommend it. Its pacing reminded me of KSR's The Years of Rice and Salt, and I think the book's achievement is very similar to that previous work's. It is not a spellbinding narrative, but rather a travelogue than manages to be both artistic and intellectual. In short, 2312 paints a sweeping and realistic portrait of a very interesting world. In Rice and Salt, that world was an alternate Earth on which the medieval Black Death killed 99% of Europe rather than a mere 33%. There the author rather ingeniously covered many centuries of this alternate history while keeping the "travel companions", his main characters, along for the ride, and the sum experience was a historian's fantasy. In this book, the world explored is the entire colonized Solar System and the events taking place cover only a few years' time. Robinson manages to physically take the main characters to almost every subsystem around Sol - Mercury, Venus, Earth/Luna, Mars, the asteroids, Jupiter, Saturn, and Pluto/Charon; some more than once - while showing off to the reader a quite plausible +300 years future. The experience is both a historian's and a space exploration enthusiast's fantasy.
