This has been my experience as well. Fans peeing in the open in front of children at a tailgate when there were portables near by was the worst. Little is worse than a belligerent drunk.I picked Wisconsin as I now live in Wisconsin. When I was in Iowa, I would have probably said them.
My experiences have been better at Iowa for road games. Certainly the normal annoying fans that heckle. But at Wisconsin I've had drunk students get in my face on multiple occasions.
But for home games, it's been the opposite. The traveling Iowa fans have been much worse.