I went to King's Island as a teenager. I went to visit/meet my pen pal in Indiana and we went to K.I. one day. I had fun.
We though King's Dominion was kinda lame. Did NOT have very good theming, that's for sure. There were some neat things, but it does not even compare to any of the Disney resorts. Plus, having to go in the summer SUCKS. Wish those places were open year round. I don't go to WDW in the summer due to crowds and heat, so I would rather do ALL amusement parks when they are less crowded and less hot. Oh well, it was an experience.