I think movie!Tony and movie!Steve definitely have much much more in terms of opposing characteristics / things-which-will-bring-friction than their comic counterparts. So I can't actually see them get along from the get go, especially if the whole Howard-related-baggage is going to be floating around, in the gravy as it were. ;)

But yeah, the friction should ultimately resolve to bantery kind - where they may snark at each other all day long, but they *and* everyone else knows they're two-of-a-kind and have each-other's-back. That's definitely very very important! (And the way RDJ and Evans seem to fanboy each other in the interviews? I think it's going to be kinda fine! *optimistic*)