In my opinion, the best way to get a system that sounds good at low volume is with an SET and a pair of sensitive speakers. As I have improved the quality of my system, every detail, especially the digital, the less I need to turn it up, i.e., the better it sounds at low volume.
Point number 2: The bigger and more powerful the amp you buy, the less likely it is to sound good at low volume.
I won't name names but I had a very powerful amp with a better-than-average reputation which I bought to drive some Martin Logans. Switching to a much more sensitive speaker pair, I was not impressed with the speakers...I was about to sell them until I heard them with an SET. the powerful amp was gone in a week. Currently using a 2 wpc amp while a custom 4 wpc amp is being built.
The ability to sound good at low volume is important to me. I tend to listen many hours a day while doing other things on the computer (like make this post) so I can't use high volumes that would fatigue my ears.
Jerry