Carver's biggest plus over Wells Fargo is that it is filled with a lot more Hawk fans. It is also nice how there really aren't any bad seats at Carver. Wells Fargo doesn't have too many bad seats but I personally don't like how that top level, the 300's sections I think, are very dark with no lighting up there, I'm not a fan of that.
Taking the stadiums themselves into account and Carver has no advantages over Wells Fargo. Concessions, bathrooms, crowd flow, parking, all are a lot better at Wells.
On a scale of 1-10 this is how I rate each.
Concessions, Carver gets a 2. Lines too long, methods for food prep take way too long and aren't enough concession stands to alleviate this.
Wells Fargo gets 9. 1st they have multiple levels with concessions, unlike Carver that has 1 level, which helps with lines. Next they have everything from domestic tall boys to craft and micro brewed beers to several full bars. Food-wise they've got the same nachos, hot dogs and popcorn as Carver but they have more pizza options, BBQ, sausage sandwiches, etc. Wells does not have the Carver soft serve but that line is always nuts at Carver.
Bathrooms are a similar deal, multiple levels and more of them at Wells means usually no line and when they are there they are shorter and move faster than at Carver.
Parking in Iowa City sucks in general. Downtown Des Moines has several public parking ramps, plus you can easily park at the stadium, yesterday it was $8 to do so.