If your speakers compress at all within normal listening levels (i.e. other than the ear damage zone) you have crappy speakers and/or a crappy amp. Also the thing with amps sounding good is the overall design which should produce a great sounding "first watt" and the following watts are simply gravy. The speaker impedance and efficiency will pretty much tell you most of what you need to know about matching an amp to speakers, but it's gotta sound good to YOU. I've designed (and mixed with) systems for live sound using multi thousand watt amps and speaker systems that in terms of efficiency and power handling make home audio gear look weak and silly, but in my active listening home rig I use a 12 watt per side single ended Class A amp with reasonably efficient mains and a couple of powered subs…it will play louder than I need it to and sound sublime with any either calm or dynamic music I put through it because it's supposed to.
power
is more power better than enough power? I know efficient speakers don't need a lot of power but do you really need more than enough power?