We camped at the Jellystone years back and had a great time! We don't usually camp at private campgrounds because of how close the sites are but this one was ok site wise. Not the best but not the worst either. The campground was clean and had a lot of fun activities. We would camp here again (only if we could fit now coming from a 24'TT to a 38'FW! ).
Corbin KOA is a very clean campground, but not much to do. We never stay in private campgrounds either, but this would be a good stop over. Havent been to Jellystone in 15 years, but last time I was there it was ok, kind of run down but there was alot to do in the area.
We stayed at the Corbin KOA in 2008 and we found it a very nice campground, it would have been especially nice if we had someone camping with us. They had gravel pull throughs where we were and patios that 2 people shared. We were at one end and a lovely family with a brand new puppy was on the other end and the kids loved the puppy. We were across from the pool that the kids loved, they also had a hayride one evening that we went on. They had a miniature golf course that the husband and kids played, they picked up the equipment in the office. Also in the office was a huge TV with a wi system for the kids to come in and play games on if they chose too or watch movies. We also don't usually stay in private campgrounds but we were in the area to see Cumberland Falls and we were not sure if the state park there could have handled our rig. We also had to take the oldest daughter to Harland Sanders original restaurant.
We stayed at jellystone last year for easter weekend and we had a blast. My kids ask to go back and they are 12, 11, and 8. They had lots of activities; their favorite was candy bar bingo. You brought a candy bar as your entrance fee and we played several rounds of bingo and the winner got like 40 candy bars each round. Like we needed 40 candy bars. My husband had to rent a golf cart because all the activites were "up hill". Him and the dog had fun riding around the campground. I think you will have fun.