I OC'd my Springfield XDm 9mm through the Gun Show in Mason yesterday. They put a pull tie around my trigger to hold it back. A few people congratulated me for carrying it openly. One vendor asked if I was willing to part with it. I told him no and that I had just bought it last week. Everyone treated me pretty much normally.
Then again, I don't think I should expect any hostility about OC from people at a gun show. I carried it with me because I was shopping for accessories (namely lights) and I wanted to try them on before I bought them.