Mapman,
I tried rearranging the room last week, turning everything 90 degrees (so the equipment is set up along the short wall) and bringing the speakers further into the room. The results are quite a bit better. There had been a bass node in the previous arrangement which has disappeared, and the imaging is more spread out. It is still not optimal, due to the room size, but it is better.
Knghifi,
The amps are plugged into the Bybee. I have limited outlet space in the room (just a single receptacle), so it's partly a practical matter. Even with the amps running through the power conditioner, though, I haven't felt as though the dynamics have been compressed.