I have had more than a few pair sound good in the showroom, that left my house after a short stay. Most were not returned. They were sold to friends or on sites like this. Some sounded good in one or more of my systems, but I could not make them work in the room that I had purchased them for. These include Martin Logan Motion 60's and KEF R700's. Interestingly enough, the smaller Motion 40's sounded great in any room that I tried them. I have also had LS 50's sound good in all of my systems and keep a pair in the house. I currently am in the same situation with the Mofi Source Point 10's. They were fantastic in the showroom, but are too large physically for the room that I purchased them for. They wound up crammed into the corners. I can't use them in my other systems (WAF or same size problem}. I view this as my problem, not the dealer's.
In the past dealers have worked with me, but I never expected more than store credit. I never asked for a refund if the product was not defective.