I'm loathe to give the book 3 stars - I'd give 3 and a half if I could. I just have mixed reactions to this book.

Firstly the good. When this book comes alive it really, really does. It takes flight and soars. It isn't just the ideas, but the execution of the ideas. This book really has a sense of wonder. There are wondrous sights heaped upon wondrous sights as we soar from planet to planet, all beautifully evoked. The opening on Mercury is a great hook, and convinced me to buy the book in the first place. Another scene of note is the return of extinct (on Earth) animals to Earth from the terrariums. Thousands upon thousands of animals descending in bubbles, floating gently to the Earth. It sounds ridiculous, I suppose, but it really works!

The characters are strong in this novel. The main characters are Swan and Wahram; Swan is mercurial in nature, and Wahram is saturnine. Guess where they live - that's right, Swan is a resident on Mercury and Wahram is from Saturn! On one level the book is a love story between these two, and an effective one at that. My favourite chapter, weirdly, details them trapped in the work tunnels under the surface of Mercury and they are just walking kilometre after kilometre. It's a tedious journey taken to the extreme, but it really allows their relationship to develop and flourish. Other characters of note, simply because I liked them, are Pauline (Swan's qube - a quantum AI embedded in her head) and Inspector Jean Gennette, a tiny detective investigating acts of terrorism in the solar system.

Interspersed between the main story chapters are numerous sections titled Extracts(n), Lists(n) and Quantum Walk(n). The extracts allow infodumping to occur, but that, I think, is an unfair description on my part. They are very enjoyable reads, some of them written in a delightful instructional recipe-book manner, and very informative. I won't say much about the lists and the quantum walk sections - I'll leave them for the reader. All in all they support the story, and despite the fragmentary effect, do not detract from the story.

So, onto the bad. The 'main' story, it appears to me, attempts to be a thriller, or a mystery, and fails completely at this. Not because of the structure of the book, but in the pacing of the story in the 'story' sections. I feel it has to make concessions, here and there, to the 'wonder' elements and the 'love story', and so the 'thriller' element completely loses any momentum that I think needs to be generated to make it effective.

It becomes very difficult to retain a sense of what this book wants to be, and makes for a very frustrating read, and at times, frankly tiresome one.

It is nice to read a SF novel that is optimistic, and positive, about our development into the solar system and maps out a pro-active future, as well as being realistic about Earth's future (I LOVED the fact that in 2312 this period we are living through, 2012, is known as The Dithering). There is always a strong sense of community, work ethic and respect for art (music, literature, fine art), and its integration into human society, and how it shapes us as humans, in Kim Stanley Robinson's work, and that continues here. It just fails somewhat as a whole, despite having excellent parts to it.

Edit (7/7/2012) upped to 4 stars after I've been thinking more about it.