What I liked: 
 The AI as a narrator. Fantastically creative character exploration, dynamic prose, exciting dramatic problems. The midpoint turn [spoilers] where the ship becomes an active participant in the story was inspired and drove me through the end. 
 Didn't like: 
 The last chapter. Took me as long to read the last twenty pages as it did the middle 100. Partly because it was back in a 3rd person narrative, all the action was over, and it was heavily didactic. He actually introduces a straw man and punches him in the face. 
 [Spoilers] 
 This book didn't really get me inspired about exploring space, or even the solar system. In fact it was pretty discouraging, so I can understand why people are criticizing the perspective he's advancing. The message does seem to be Earth-centric environmentalism at the expense of space exploration. It's especially rankling to those of us who care about the environment, but still want to see more space exploration. Aurora has an important message but it can come off as obvious, preachy, cloying. Personally, I can forgive Robinson's lack of finesse in the conclusion for the riveting, refreshing science adventure that came with it.