Br3098,
Thanks for your response--and I know my room does need some treatment, as it has wood floors, plaster walls, and a couple of very big windows behind my listening seat. I have bookshelves behind the speakers to provide some diffraction (and they do help the treble and soundstaging; I checked with and without). The speakers are far enough from the side walls (7-8 feet) that I don't think first reflection points are an issue, and the ceiling is high (12 or 14' I think) so that I doubt that I'm getting many problems from it. The floor and windows are problems, though: I'm looking for a rug and planning on some curtains. When I walk around the room or listen from another room the sound is very "live".
A few observations since I wrote that last post: I've moved the speakers again to do what I'd first intended and set the room up by the rule of thirds. At first I placed the speakers closer to the wall thinking that would give them some boundary reinforcement, but now that they're 4.5 feet into the room with my chair 4.5 feet from the back wall the bass has actually filled out and seems more solid. This is a good improvement, though I do think the treble character seems much the same as before--possibly because I'm closer to that very reflective wall and windows behind me? Second observation--after I wrote I switched my IC from a Tributaries Silver to a cheap pair of Markertek interconnects and found the treble a bit smoother and better integrated. I've never invested much in cabling and it may be time: my speaker wires are Tributaries-branded 12G zip cord that I've had forever. Now I'm thinking of trying Anti-Cables for ICs and speaker wire--they'd fit my budget and hopefully be a step in the right direction.
In any case, I'm going to take a little more time to try things out and see if I can make these little guys work for me. I have a few hours tonight to listen and work on set up. Thanks again for any and all help along the way.