a musical reproduction system transparent enough to let the best recordings reach their full potential, yet not so ruthlessly revealing as to make lower sound quality recordings be unlistenable!
Actually my experience is that a transparent system will bring out the best in any recording, no matter how flawed. I want to hear what the artists were doing, warts and all, I can listen through recording errors and would much rather it was given me straight than sugar coated. Certainly in my current setup I've yet to find a disc "unlistenable" and am enjoying lots of things I'd previously written off
As to the Sopranino -- while it added extra clarity, air and space there was certainly some discontinuity between it and the Be tweeter on the Q3 and in the room interaction I found the need to tone things down -- since then I've gone to more transparent settings on the SR gear (silvers vs golds) and no longer feel there's any high end discontinuity -- but it's certainly still on the "hyper detailed" end of the spectrum, kind of what I like I think