What knocked me out about this book was not the science half of the story, which was great, but the depth of the characters Wilson creates, and varied situations that occur and the breadth of the possible responses people have to a literally incomprehensible change in the way the world works.
Look, I love science fiction, I love the literature of ideas, and I read those books all the time. But sometimes where some of the genre falls down is in creating characters that are not made out of cardboard, not just mouthpieces for the latest idea or bit of science. This is not one of those books. The three main characters, and many of the minor ones, remain vivid in my mind weeks after reading the book. And it is because I care about those characters, about their struggles and attempts to adapt to a fundamentally different reality that I really enjoyed the book.
Not to mention that when the reason for the Spin was revealed, it blew me away. I was convinced that we might never find out why it had happened, and I would have been okay with that, because it was not necessarily the point of the book. However when the answer was revealed, it was the best kind of reveal - it made perfect sense with everything that had happened so far, and yet I never would have guessed it.
I will be seeking out much more Robert Charles Wilson to read in the future.