Which receivers have decent stereo performance?

Well if you can use the Yamaha as a preamp for now.I would use a seperate amp or amps for the Soliloquy 6.3s.The speakers are so efficient the Yamaha doesn't sense a load so it want put out any real power.
Two Monarchy SM-70 monoblocks used ($700) will give you an enormous improvement!Even a Van Alstine 120 D will take them to a different level.You can get some Acoustic Research directional interconnects from bestbuy.com for $13.00(shipping included).Parts numbers are AP0-30 or AP0-31..depending on lengths.Try to stay with the shorter lengths if you can. These interconnects do not know their place when it comes to price verses performance! Theres a Van Alstine 120D for sale on Audiogon right now! $450.00 plus some AR ICs will put you under $500.00 total and the improvements will be huge!

Trust me on this one you want be disappointed!
Good Luck!

I would go with a Marantz or a denon. both are pretty good at music. A friend of mine have almost the same system set up, I have a Yamaha RX-V800, and he has a Marantz 7300. his sounds much better for music

I'd second Gmood1 suggestion of adding an amp. I have the RX-v2200 and was not happy with the 2-channel sound either. My Paradigm Studio 60s are not very efficient and the Yamaha didn't have the umph to drive them. I added an Odyssey amp and was amazed at how much the lows and the mid-range opened up. Add the amp, not another receiver!

If I follow Gmood1 advice, I need to unplug/plug the speaker cables when switching from stereo to HT from amp to receiver, right?