Just a note about shows
Shows have some of the worst, saggy, highly impedance, overloaded, noise polluted mains on the planet....way beyond what an average conditioner can fix
Shows are also literally EMI/RFI soup and who knows what the quality of network feeds are like given the amount of bandwidth being consumed.
The rooms are generally asymmetrical and the furniture is removed to make room for seated listeners, who come and go, changing the room’s RT from under-to over and occasionally perfectly damped.
Speakers are set up to allow the maximum number of listeners to get a reasonable impression of performance, so there really is no sweet spot and most seats will not enjoy proper channel balance and symmetry.
The partnering equipment is often loaned and may well include items not fully run in. In addition, all equipment has been packed, transported and only installed the day before the show. In some cases, speaker manufacturers may not really know the sound they are aiming for
Typically the hotel has very high levels of ambient noise...while this may not be heard directly it certainly masks a lot of ambient detail and subtlety .
Earthing at shows is probably both highly polluted and high impedance.
Foot traffic and multiple systems will massively increase floor borne vibration
So all in all, if any manufacturer or dealer can achieve even half decent sound at a show, it demonstrates an extraordinary level of skill, or a highly refined and stable process based on a carefully chosen set of ‘show components’ in order to make the set up as reproducible and stable as possible.