Originally Posted by Picard Sisko
Exactly. As much as I love RDJ's Tony Stark, it feels like he is just acting as... himself.
In an interview after the People's Choice Awards, RDJ said that he sometimes goes into character at awards shows and for interviews because it's just easier and more fun that way. Downey is not "playing himself" in those movies, he's playing Tony Stark whenever he's on stage.