With a movie like this you wonder how all of the otherwise, main characters will work together and support the story. No problems here. While as might be expected, R. Downey Jr. comes across largely central, it is still a good mix and IMHO the best scenes in the movie involve the generated Hulk character. With that kind of successful melding of characters, Hollywood-scale egos and even computer generated characters; you have to give it up to the writers and director to make this the successful film that it is.