@hilde45 - I think your initial post with its posed questions are fascinating, personally. Before going down this rabbit’s hole, I don’t think I would have been able to relate. But I’ve spent the last 6 years working remotely (which now feels like a bit like being under house arrest, but that’s another topic) and spending an inordinate amount of time streaming and discovering music. I have an office system, so my listening goes on throughout the work day too, albeit at low volumes with classical or jazz.
During this time, musical reproduction through audio equipment became a fascinating topic. Of course the room acoustics plays an outsized role in all of this, as does one’s emotional state, etc. But equipment does sound different, especially when paired together in new configurations. Through the years, I began to develop a sense of all the criteria you’ve listed in the original post, but it wasn’t organized in my mind coherently. That said, I know I was listening for it.
I’m still a newbie to this audio world and have yet to attend Axpona or similar events, which I’m looking to do in the future. I have visited lots of retailers and demoed and purchased equipment that I now have in my house. The class d discussion has a long history - predating my interest by a long mile. At the heart of the topic, at least in my humble eyes, is whether modern class d can deliver the emotional experience we ultimately want - are we moved by the music, does the equipment allow us to get closer to the performance - which I assume is how we all started down this addictive path.
When I saw your original post, I couldn’t help but share my own recent experience with these AGD Audion mkiii amps. They’ve delivered on the emotional experience I have sought, but without having to worry about tube’s going out, or the inevitably issues they seem to bring.
I still love my other amps. The Gryphon 120, in particular, still wows me on a daily basis. Just an amazing amp, as are they Qualiton and CJ amps. They are just a different flavor of joy.

