I always wonder what sort of sign it is when I finish a sci-fi novel and want to go read some quantum physics just to encounter something sensible.
Egan's book was fascinating, if remote. I found the absence of FTL to be a particularly brilliant touch and the way that he seems to push development forward in such a way that it seems natural that we should have arrived there yet completely incomprehensible how it happened s very cool.
In the end, my biggest problem with the book was in its characters. This is very much a stereotypical hard sf work, with the focus on technology and development and characters who exist to move the science forward. And they were surprisingly good...for the genre, which is why I wish they were just a little bit better. It's not that Egan doesn't do a good job, it's that he's talented enough to mesh character and technology, but doesn't get the balance quite perfect.
Though perhaps I'm biased, as a reader who judges books based on character.
In any case, I enjoyed this bewildering trip through speculative science, though I can't decide if it has encouraged me to pick up more of his works or scared me away.