I haven't read any of Powers' later works. I had trouble getting into both The Anubis Gates and On Stranger Tides. That being said, I still plan to try Last Call.

I enjoyed Downbelow Station when I read it, but that was years and years ago. The Faded Sun and The Chanur Saga are my favorite Cherryh books.

Regarding McDonald, I actually liked Brasyl quite a bit more then River of Gods, but that's just me. :)