Considering all that The Avengers had to accomplish as a summation of several comic book movies, having to incorporate multiple storylines, further re-flesh out characters that had already defined in previous movies and provide that summer blockbuster feel all while making sure nobody got pushed aside, I don't see how anyone could come away being anything but impressed at Whedon's work here. He treated the material carefully and managed to accomplish what the X-Men movies(save the last) failed. To create a real character driven drama with the ability to tell a story thru multiple viewpoints.