Cincinnati Scale Modelers put on the event, and they do a good job. It's not huge, but it's a pretty sizable event. There are quite a few vendors, and it makes for a fun day. I have no connection to the Cincinnati Scale Modelers, but I'm tempted to stop in on one of their meetings.
Here's a link to their page. Look under their "events" tab for info on the show.
http://www.cincyipms.com/index.htm
Is it worth two hours of drive time? Yes, I think so. I think you'll have about four hours of fun. It's not like Ohio has a ton of modeling events.
Also, there are always some very impressive models displayed there.