Thanks. I did make the QRD. I didn't do any calculations beforehand so it's really more art than anything, but I do think it helps. I also have some egg crate foam on several of the walls, and I ahve a lot of absorption in the room including behind the speakers, at first reflections on the side walls, and tons of it behind my listening position. It's amazing how good this space can sound even with large speakers like the Cornwalls.
The setup as it is now has a huge soundstage that extends well beyond the speakers horizontally and has a real sense of scale to it. Imaging is quite nice, though of course not as good as it was with the open baffles I was using before.
The biggest compliment I can pay is that I have a bit of a hard time describing the sound since whenever I listen, I get lost in the music. Honestly, that's all I really want and these speakers do a better job of allowing me that than any others I've had.