Captain America: The guy who has been punching Nazis non-stop for 6 friggin' decades.
Iron Man: Rich playboy/washed-up drunk.
Is that really supposed to be a tough choice? Can anybody explain to me why Spider-Man and Thor are apparently siding with Tony Stark over Cap? Why does Thor care about the politics of mere mortals at all?
I suppose if Cap where on the side of oppressive government sanctions against supers and Iron Man was for vigilante action, you might be able to make a case for siding with Shellhead. That might be an interesting scenario. But Captain America is on the side of unauthorized badguy punching and Tony Stark is for NSA wiretaps.
As the man himself would say: 'Nuff said.