I make sure that I can play ANYTHING up to about 100db on most of my systems. Because there are those that listen at that level and then there are those that listen at 75db and also 85db. There can't be any issues at any level in my rooms.Then put them to the test at the dealers place , 2 house CD s and 2 with orchestra / piano is all it takes with the volume right up there.
Expect no mercy for that kind of $$$
Although putting speakers to a test, especially large scale speakers to a test, at a dealer's showroom, has NOTHING to do with what will happen in the customer's room. ESPECIALLY WITH BASS, which is room dependent.