More power for moderate listening levels?

Hi,

I can't seem to find good information regarding the effect of relatively high powered amps on low to moderate listening levels. I have a low powered class A amp that sounds wonderful at moderate volumes but not surprisingly shows signs of strain when cranked up. I am contemplating an upgrade that would bring much more power to solve this problem. However, since I don't play music really loud that often I'm wondering if the upgrade is really all that necessary. It would be worth it if the reserve power of the new amplifier improved sound quality at all levels.     

Thanks for your help,

Brian