First, most people's living rooms outperform most store demo rooms. Unless you are building a treated room within a room in the store, most of the time proper setup yields better performance in the clien't's home than it does in the store (at least in the US). Did I mention that US commercial construction codes suck?
I agree with you. Experiential demos are all about credibility. The dealer is showing his capabilities or lack thereof when he provides a demo experience. Every detail should be addressed. The experience sets the bar. It's not just about sound either. I remember once watching a dealer lose a large room build/system sale because the outlet plates were not installed in the dealer's otherwise spectacularly built room. The message the client took away was that the dealer could make good sound but would likely never complete the job.
Lastly, all gear deserves the best effort.
