I think David Brin should be way up on the list - tied with OSC. The “Uplift Wars” series was marvelous. It had a complete eco-system and multiple alien societies completely described.
I really dug the Brin I have read. The ‘uplift scenario’ is a really great idea. John C Wright and Brin are fans of each other’s writing to my understanding, but they have locked horns on the interwebz over politics and philosophy.
Brin is much harder than Wolfe or Vance, also harder than Wright but not by as much. Did you catch him doing commentary for science channels’s Masters of Sci-fi?
Freegards