Mine had 6 miles on it. If I am buying a brand new bike, I would not buy one that someone else test rode. A ride after uncrating for a few miles is one thing, but letting people take it out turns the bike into a demo and used in my mind. I would expect a discount if that was the case.
Mine was just out of the crate when I bought it.(09 Ultra) Asked the salesman to put about 50 miles on it before I picked it up. If something was wrong or loose I wanted it to show up before I took it-- I've done that on every new bike in the past. I think there was 45 miles on it when I picked it up.