I have first come across Greg Egan via Twitter, and this is the first book I read by him. Reading his tweets and his website convinced me to try reading his books; "Diaspora" was then a Christmas gift.
One thing I really appreciated is the effort he put in coming up with alien life that feels indeed alien and is not the usual anthropomorphic species a la Star Wars / Star Trek (that is, some dude in a costume - optimised for cosplaying). We have giant arthropods, stuff you could find in a dirty Silurian pond, beings that are embedded in constellations of thousands of stars (good luck cosplaying that), and the weirdest of all: beings that are not necessarily beings at all, but rather extremely sophisticated patterns in some type of chemically-fuelled cellular automaton.