The most sophisticated sound you ever heard

Personally, the best concert 'sound' heard by this mortal was @ a Blue Man Group concert in Houston some *eh* 15 yrs. ago....

Cynthia Woods Pavilion....what caught my attention was the 'mix'...

Nicely 'balanced'....clarity top to bottom....for a 'percussion-heavy' performance, all the players 'presented' as nicely as one might experience at home....*S*...For a 'novelty band' (MHO, but I enjoy a little humor in my musical diet....)

(What was amusing was that the attendance was 'light'....'bout +/- 1/3rd of a 'typ. crowd' for that venue.  The next time BMG 'came to town' about 3~4 months later....SOLD OUT within an hour (but was an 'indoor' show...*G*  'News travels quick...' )

I think I get what you mean by sophisticated.  If you mean something subtle, not emphasizing too much, gets out of the way but is nice and detailed.  Definitely not bass heavy.  In which case for me that would be rebuilt Quad 57s by Wayne piquet.

as a comparison the next 4 for me that I’ve owned or currently own would be in order:
Magnepan 3.7
Quad 63
Harbeth super hl5 plus
Sonus Faber Cremona m
Kef ls50

In terms of speakers
Classic Audio Loudspeakers
Audiokinesis
Sound Lab (IMO,IME the state of the art in ESLs)
Maganplanar (the 20.7 being one of the better deals in speakers)
Analysis (improving on the old Appogee design, bigger and easier to drive)
Pure Audio Project

In terms of shows, two stick out
Hawkwind- this was the first rock show I went to see while only 17 years old. There was a guy brandishing swords on stage (Lemmy) and some naked lady dancing on stage

Yes- Topographic tour, about 1974- This show employed enormous Roger Dean props, one in which Alan White's dual drumsets were installed. Tympani played on stage as well, lasers, crazy lights and extended versions of songs that took an entire LP side to play...

Anne-Sophie Mutter and the Boston Symphony Orchestra playing Tchaikovsky's Violin Concerto.

When we returned home from that concert, I fired up my excellent audio system, very very good, but no match for the sound in Symphony Hall...

The MBL room at a THE show a few years back..... pretty amazing