I guess my answer to your question is another question - what is sound quality?
Personally, my interest is in the music itself. I play mostly rare stuff. I'd rather hear that in almost ANY quality than hear the run of the mill stuff in audiophile mode.
Often, the source material for my station isn't the best, so going all anal about the 'quality' wouldn't make much difference.
You also have to take into consideration where you listen. It often doesn't make much difference re the quality where there's plenty of ambient noise, such as in a car, or a backyard, etc. I suspect that very few, when listening to the radio, are in a quiet room, doing nothing, while ruminating on the quality of the sound of the station that they're listening to. If you're going to do that, you're likely going to listen to other sources, not radio.
That being said, I want my station to sound the best (from my viewpoint) that it can. But also get the maximum range that it can (so at the very least I can hear it while going about my business locally), without sacrificing a lot of that mysterious 'quality' element. Which is what I try to do. And attempt to achieve results which are entirely subjective.
When I stream, I don't apply any processing at all to the audio stream. It comes through in all the natural glory of the source material. But my stream is limited to 48KBps mono - mono because most the music (and talk) is mono, and because I want to maximize the number of simultaneous listeners that I can support (I run my own server). So again, a tradeoff. One which I'm willing to make.