I'm wasn't implying that different cable may or may not sound better or different in a hi-rez system, although in a pure sense, properly designed and built for the application, they should do nothing at all to the sound except get it from A to B. If you can reliably and repeatedly hear a difference, better or worse, go with what sounds better to you in your system.
As both an audiophile and a career tech I am sometimes at odds with myself over WHY this or that sounds better, worse or simply different, when technically I can't explain why there should be any difference. Electrically and mechanically gear does "settle in" after use, that I buy, speaker cones, amps, what have you, but WIRE?? Maybe it does and I just can't hear it. I've never had the funds to buy multiple expensive cable sets and play with them.
As for high end MIL gear, if different wires made it "better", trust me, Uncle would be only too happy to buy it with your tax dollars. Much of the gear I worked on in my career costs more than my house and cars together. Purely from a technical standpoint, wire is wire as long as it's applicable to the intended use................Does one "sound" different than another, yes I've heard that myself. I simply can't fathom why a hundred hours of usage should change the way it behaves or sounds..........call me ignorant, I've been called worse :)
Our hobby is to a very large extent, subjective, and there in lies the source of many of these debates. In the end, buy what you like and can afford. If it sounds good or better to you, enjoy the music. Wasn't trying to "P" on anybodies corn flakes here, just expressing my personal opinions and professional experience.
If you REALLY want to improve the sound of your system for a fraction of its cost, address your room acoustics. Little room for debate on that one and the audible difference is obvious and significant.