One of the most realistic and "real" worlds from a socio-historical pov I've ever read.. Palmer's world building does for history and sociology what peter watts does for biology and neuroscience.
I really like the worldbuilding, but I don't think it's any more "realistic" than a fantasy novel or galactic empire science fiction. In particular, the complicated governance stuff is in there because it's fun, not because it would actually work. There is straight-up magic as well as ambiguous possibly-magic.