I'm a current intern who interviewed at Iowa this past cycle and matched elsewhere in the midwest so I can share some thoughts. Iowa only filled 1 of their 2 spots through the match this year and let me say I was surprised. This is strong program that I think was burned by not interviewing enough candidates. This past year I believe they only interviewed 18 of us.
Based off my memory (I wasn't a person who took notes at each interview and have since thrown out much of the propaganda), the program itself is relatively small, but I was impressed by the department. They have a relatively new and very nice cancer center. Strong head and neck department was mentioned multiple times. Very physics heavy with about 11 physicists (I think) on staff. They even call the department something like the cernter for image guided therapy or something like that. Friendly residents, program director was nice-although a little on the quiet side. No away rotations needed. They have their own in department MRI and PET, so they do a lot of research with those toys. Speaking of research this was the location where Holman was pushed the hardest of any I visited. 2 current residents on Holman and one recently graduated. They even took all of us over to the lab space and had a separate meeting with the director of their PhD program talk to us. They, like many others, made mention of protons, but I believe this is not a certainty as of now. Iowa City is a pretty nice college town, good cost of living, but once you are outside of town there isn't much for a good distance. Overall, I like the program and feel it would be a good learning setting, but the location, even for a midwesterner was less than desirable.