I had Slonczewski as a professor for a class called "biology of science fiction" my sophomore year of college, and I think that ruined any of her books for me forever. She's absolutely insane and forced us to read several of her books and the only thing she really had to say about A Door Into Ocean was "look! It's a reverse Dune! The ocean is a desert! Clever, huh?".
I liked Brain Plague a lot better, but again, I can't seem to get past her appalling lack of anything interesting to say about it aside from "look how cool this book is look how cool I am I wrote it!!!"
On a completely different subject, I know you like Steven Brust; have you read To Reign in Hell? I'm trying to decide if I want to. I love his novels about Vlad, but this is a bit different!