I currently have the Onkyo NR-900, it's a nice featured receiver, but it seems to be over protected on the watts when driving 4ohm speakers. In the manual it states 110w per channer @ 8ohm with 2 channels driven from 20 Hz to 20kHz, and 145 @ 6ohm 2 channels driven from 1kHz. The only thing is says about 4 ohm is 2 x 220 Dynamic power output (stereo).
There's a few things about the receiver that I don't like, that's the net tune radio (doesn't work), and the lack of power. It get's loud, but it just doesn't seem to have enough there. When listening to music I can turn the system all the way up, it's loud but not earth shattering. It didn't knock anything off the shelves, and I couldn't listen to it very long at that level, but I shouldn't be able to turn it all the way up and be in the same room 10 feet from the speakers. I'm currently searching for a replacement.