Granted it's a control is not a football stadium but the principle is the same. Have a neutral designer design the actual stadium the Vikings want to build, then have the contractors all bid on the same design. That would have given the Vikings real number to put in front of congress when proposing the stadium that wouldn't change significantly once it's passed.
I don't like the idea of a retractable anything, sounds like a waste of money. It would only be open for what, 2 or 3 games at the most anyway? Plus if any part of the stadium opens up it'll mean an awful shadow problem like Lucas Oil Field. Those shadows were really hard on the eyes when we played the Colts in September. All stadiums with a retractable roof have terrible shadow problems.
It will look similar to the Cardinals