RV, FWIW, IME, I'd bet that when you were listening to music over a mid fi system you were not focused on its recorded sound so much as you were exploring new music or the alternative performances of music of which you were already aware. From that experience you developed preferences which you carried forward into your development of a high fi system. Music, or performances of such, dicated how you wanted to hear it over your hifi. By way of example I fell in love with Kleiber's version of Beethoven's 5th. Even now, I don't listen to other versions by conductors whose version doesn't draw me in regardless of the competence of the recording.
Not so much with Richter's version of Mussorgsky's Pictures (1957 live at Sofia). To me there has never been a better performance more ineptly recorded as this. I do not take it off the shelf but I do find that I there are quite a few newer performances, better recorded, which I can easily enjoy.
I guess the importance of the sound quality today is greatly influenced by the importance of the music (to me). Much of the music is well heard in my mind so what I hear is not so important over my hifi(?) system so long as the sound is not offense to my hifi ears. This morning I'm listening to RR's recording of Copland's Fanfare, Appalachian Spring, and 3rd Symphony. Hog heaven, even though I'm sure there are better (technically speaking) performance available. Over my system the sound is as good as it gets (or needs to be). Guilty pleasure.