Maybe this is just because I go to Kings Island all the time, but I'd rather walk around the park for one hour than spend a whole day riding rides. For one , riding rides all day is just boring and tiring, but walking around is fun and relaxing. I also really like people watching!
So, yeah, I miss the atmosphere most. In fact I haven't ridden a coaster there since July, and I went three times during October and once in September!