I found the Orthoganal trilogy brilliant as an experiment in character development, and extending "alternate realities" about as far as they can be extended, but they aren't as engaging as most of his other books (IMO).

I think this is more due to the fact that humans like reading about characters they can easily relate to, and Egan really pushes this boundary!

Still worth a read, and I'll almost certainly re-read them in the future.