It is a fantastic show. It was started by the steam people and you can get to see some of the old traction engines plowing and threshing. The hit n' miss engines are everywhere.
I have heard that they are featuring (full size) Otto engines this year and there are supposed to be examples being brought in from long distances. I haven't been there since 2005 and that was the year I started into this crazy hobby so I wasn't paying a lot of attention to the models. I'm going to try to get there this year because it's (only?) a 4 hour drive for me. There isn't anything closer to me that has any displays of models so it would be fun to see if there are really "real people" that do some of the same things I do.