Creege, I'd didn't mean to imply that your idea was crap (if it appears to you that I did). And I can understand your frustration with reviewers who talk on at length about how some piece of music sounded on two different components, especially when they have music which you have never heard - it just becomes meaningless (to me at least).
My poor attempts at humor aside, what I really believe is that if I am talented enuf for you to respect my opinion in the first place it really doesn't matter what type of music I listen to in order to reach an opinion, so long as you know my equipment, my room, and my personal tastes. If you don't know me or my things and taste, you really have nothing to work with, except your subjective reaction.
Another problem, for many I assume, is that records that I listen to for judging equipment are records that I have come to appreciate over the years for certain traits. All are NLA on the market, except used, and only a couple are in any sense audiophile disc's (which I personally dislike for these purposes as many of these records are so well made that they will sound great over crappy components). I tend to choose discs that challenge certain aspects of electronics. For example, I have a solo piano recording that in one brief section has a very complex and loud mixture of notes which on many components becomes harsh and unpleasant, and on others dull and rolled off. If its bright and musical, then the component is handling that part of the spectrum perfectly. The record also works well on system set up as often the problem is in the first relected sounds mixing with the first arrival sounds prematurely.
Sorry for dragging this out, I wish I could be more positive about your idea, but I think this is an area in which we must all, ultimately, find our own way.