Definitely not guilty on point A. Somewhat more guilty on point B. I have, however, definitely expanded my musical tastes. My method, though, is usually through www.allmusic.com - I hear something I like, and go out and research it. Pretty soon I'm following all the Similar Bands links, etc. and I've got a list of CDs to buy. Then, when I have bought a CD by several different groups, I find that some of them are better recordings than others. I am MUCH more likely to buy other CDs of a groups I find this way when the first CD I listen to is of reasonable (or great) recording quality, and much less likely if the recording quality is poor.
I definitely admit to picking certain CDs to listen to occassionally based a great deal on their recording quality, but it's in a genre I like. Sometimes I just want to hear the rig do it's thing. -Kirk