Thanks for that @mulveling - I'll take it under consideration before tossing out the baby with the bathwater. My friend down the street w/Stirlings just told me he went through a similar experience, but blamed his midfi ss amp (probably not too far off the mark there!). He wandered around the hifi gear desert for long enough that by the time he circled back to Upscale for a PrimaLuna integrated, the speakers had settled into the pocket.
So, I have some new confidence that time is the antidote. Joni Mitchell Blue sounded pretty good last night - better than previous anyway. Granted, the treble energy is dialed as far down as it can go and they're still wired to the LF and jumped to the HF, but the grit was definitely downd and heading in the right direction.
I have a pair of AZ Hologram II biwire on the way that might also help simmer things down.
It's also good to see the evolution of your loft space - my room is similar old world construction and 14x15x10 - and dream of some Kensingtons. They look fine! If the house were mine and mine alone (but "it's his, his and hers alone"), the Canterbury could just ride....