Agree with you on all points. Adding to the discussion regarding our ears and listening impressions with various devices. I bought a 1/2 dozen of Shunyata Sigma NR 2 power cables for my system. Well, too much is too much. I used Neotech hi-fi pure silver power cables on my amps. They are plugged into a PS20. Well, the Shunyata did not seem to have the life or zest that the Neotechs have when plugged to into my McIntosh MC2301s. I tried direct in wall and into the PS20, the connection to the PS20 always seemed better to me regardless of which cable I m using. The sigmas are on my field coil power supplies now. But, I might experiment with the Omegas with QRB technology which is supposed to eliminate the need for any conditioning.
When I plugged the Neotechs back into the amps, I had that aha, there you are moment, the sound I was missing when I was using the Sigmas on the amps was back. So, I have discovered that as you said, our ears can become objective.