After my last post, I changed something from the way I've positioned my speakers for the last 19 years: I aimed them directly at my ears using a laser level device as an aid. Every speaker I've had before sounded too bright positioned that way. With my present speakers, it now has more presence and immediacy, top to bottom. The only thing that diminished slightly was the sound stage, but that is a low priority for me as I relish tone, timbre, and presence.
Not only has the treble sweetened and aired out more than I thought possible, from there on down all notes have taken a turn for the better (and it was really nice to begin with, save that treble). There is a wholeness to the gestalt of the music that was merely hinted at, keeping me in a state of tweaking. Now I can relax. I guess this is a long winded way of saying don't forget the room, especially when something new is added. Sometimes, it's just a matter of an inch or so.
All the best,