For me, the two most impressive demos I've been to are head and shoulders above the competition.
UK Paul's modded ML panels/Concert Fidelity hybrid monos, and Bill's bespoke horns/Mayer 46 monos.
The only demos where I was really taken on a journey, virtually nothing to distract me from moments in time and musical flow.
Interestingly both systems despite being so compelling and seemingly archetype-free were quite different sounding experiences, yet both were magical in being transformative.
I'd have to agree with Bill (and they're his babies, how could I disagree with their daddy? Lol), the seamless quality I heard at his leading to pure suspended disbelief at the magical conjuring up of music in his room and thus invisibility of transducers, was on multiple levels.
A transparency borne of sheer tonal accuracy and familiarity, natural and unforced dynamics, digging deep to resolve microdynamics, and unimpeded flow/lack of room artifacts.
Cutting to the chase, and cutting out verbose audiophile checkboxes, the combination of fantastic authenticity of instruments, unfolding of music naturally, and seeming independence of the constraints of the room, really bridged extremely challenging barriers of cognitive ease and familiarity. Once these extremely hard to achieve characteristics are apparent on every piece, then a zen state of being as one with the music can happen. But so rarely does.