I saw Iron Man 3 today with some friends, and enjoyed it a lot.
In one sense this is a long film filled with lots of explosions, and a sense of scale.
But special effects do not a movie make, and the special effects aren’t what makes Iron Man 3 worth seeing.
This, and other personal issues from Tony’s past, centre the film, and certainly kept me watching.
That the film ends with a real sense of resolution, of character growth, is a large part of what made it a satisfying movie to watch.
NB: There is an easter egg after the end credits  that plays towards The Avengers 2, which I think was a wise choice.