"Pinning the cause down to a single room at the show seems a bit of a stretch to me."
No, it was definitely the room with the loud + dynamic horns. I was in there for over an hour just before leaving and no other rooms (including those with other horns) were anywhere near that intense.
Intense in a good way, but intense nonetheless, ie loud and dynamic albeit very clean with no noticeable distortion or breakup and most pleasant to listen to.
So if your goal is to reproduce the close up dynamics of a live orchestral event, I would say that system did it as well as any system I have heard. But I would have concerns about listening to anything that intense for too long or too often because it can definitely accelerate hearing loss.
BTW, my system at home and most very good suitable powered systems I have heard would have much the same result if listened to similarly. That is what music can sound like, but its effects on ones hearing if exposed too much to it should be an area of caution.