I've spent a lot of time in Iowa City and I actually have always liked Iowa's campus. With that being said. the dorm housing is a real problem, especially if you are on the wrong side of the river. Or god forbid you get stuck in Mayflower.
I think a lot of it is just personal preference. Urban campus wedged into the city, or the more separated 'island' like ISU. Some people like the downtown feel, others like the island.
I did BS at ISU and MBA at Iowa. Very strong preference for ISU for undergrad, but as an off campus grad student, Iowa was fine. Plus by that time I had money and could afford to go to bars lol.