I went to one in Raleigh, NC a few months back. It was held in a pavilion at the State Fairgrounds. Like the one in Columbia mentioned by jhull87, there were no firearms allowed, but I chalked this up to the law here in NC about no firearms allowed on the state fairgrounds property. There were a few vendors, about 20-25 and they had some good information. I'd say if you have the time and gas to spend, check it out. I don't know if I'd go out of my way again to visit, unless the classes were someone I was really interested in, but then, it's only a 45 min drive for me.
Good Luck!