TL;DR - If you're on the fence, just go for it. Double check sizing on the tables provided for the booths and be ready to make adjustments as needed for them.
We've sold here almost every year, and it's always been excellent. It's a one-day show in a university library, but it is incredibly well organized and promoted/marketed with clear success.
Two key factors for the high sales most of us experience there have been the fact that anyone can attend free, making it a wonderful event for large families (and there are plenty), and that they put the artists right by registration so anyone walking into the library's main entrance, where registration is, can enjoy a niiiiice long look at the first rows of stunning creations.
Because it's free to the public, there aren't any special restrictions for where you can and can't go, so badges aren't really needed. Even though we pay a small fee for our booths (2 for 2023 was $80), you don't have to buy badges or anything, so it's easier to have tablemates.
The library staff are extremely friendly and helpful, and every year they host a breakfast potluck in a private room just for the artists. They check in regularly and are very accommodating. One year when we couldn't get away from our table, the staff member who checked in went to get another staffer so they could team up to bring us water. That's not an uncommon occurrence, either.
The only drawback for me is that the tables they provide are their standard library tables - I believe 4'x2'? We have two 6' tables of our own, so we just decline tables in our applications and bring our own, easy peasy. And again, they are super accommodating, so if bringing tables isn't an option for you, reach out to them about using more than one per space, or other solutions.
For those who aren't aware, the University of Northern Iowa is a strong proponent of diversity and human rights for marginalized people. For instance, there are several LGBTQIA+ organizations on campus and in the community, and UNI offers SafeZone Ally Training to its faculty and staff to promote education, compassion, and inclusion. RodCon itself also has a dedicated Quiet Space for anyone with sensory issues, though they also recommend it for overstimulation, anxiety, and more.