I was just about to post this question before I saw the thread.
I use a pair of Mission satellite speakers with recommended amp power of 20-50 watts, with a Yamaha RX-V1800 rated at 130 watts per channel.
The room is small and I never crank the volume past -8dB on the volume scale (that's below half way on the yamaha's front display, around 30% of it's max volume i think) it's not too loud just a decent volume.
I've never heard any distortion or odd noises and as far as I know they're functioning properly, but am I damaging them? Should I be looking to upgrade?
With my old Rx-V2300 I bought in 2002 the power rating was less (around 100-110 watts per channel) so I never gave this any thought when I upgraded, it just sort of dawned on me now.