REAL MUSIC VS. SHOW MUSIC PERFORMANCE AT AUDIO SHOWS. PRESENTATION V. PERFORMANCE? WHY?

Very few speakers can play all genre , maybe Iam wrong example I prefer my KLH on classical. And since my Andra were voice on piano , when I play piano music I go with the Andra.Both KLH  model 9 and Andra both   are very capable, there are some music will sound good on either speakers.i think to test the performance of the system you have to play different types of music from  country, rock pop, jazz, good vocals, classical, …spend time hrs of listening my 0.2 cents When Mary Chapin Carperter came to Ravinia here in Illinois. After I listen to her Live . I realize Live is my preference over stereo system.

One time I listened to a limited edition pressing of Reign in Blood by Slayer at the record store listening station. It sounded spectacular on the store’s mid-fi cartridge/TT/receiver/headphone system. Full, rich, accurate, clear, deep, powerful.
I brought it home to my high-end system and it sounded surprisingly bad; lacking in cohesion/warmth/power, tinny.

I agree that not everyone listens to music that the stereotypical audiophile considers “good sound” (I assume this type of recording is what you’re referring to as ‘high rez’). There are a pile of cliches in this regard.  
I listen to everything. Thusly, I want everything to sound good on my system. I agree that if I was at such an audio show, not only would being subject to Diana Krall, Kind of Blue, Eva Cassidy, Brothers in Arms, Aja et. al for the trillionth time make me ill, but I would also want to hear a far wider range of music.

Play stuff like this @100db at your next show and wake everybody up. When they're awake, they may buy more things (you may sell more). 

Play it safe however, if you have flaccid speakers and amps. If the stuff you're selling is a bit wimpy, play it it safe, stick with lullabies and play Diana Krall @60db.

I would let the exhibitor choose what is best for his gear.

I would not sit there very long if Metallica ,Slayer ,the above Youtube tracks or that kind of ´´noise ´´ was playing . Bring that kind of crap to the dealers for private playback , when your choices have been made.