I decided not to see Iron Man 3 because it seems a return to old way of adapting superheroes to the screen: focus on the star, not the costume (e.g., Stallone's Judge Dredd); throw away most everything ever established in the comics about the character and/or his villains (e.g., just about any TV adaptation from the 70s on, such as Spider-Man); and those behind the adaptation are more interested in making the superhero more "believable," which is another way of saying they're not particularly interested in the character but in "telling their own story" (e.g., Ang Lee's exploring what went into Bruce Banner's rage in Hulk, or Superman giving up his powers in Superman II to live a boring bourgeois life with Lois for 30 minutes of screen time). That is, we get a Tony Stark pondering what makes him Iron Man (Robert Downey, Jr., is tired of wearing the suit, basically), a funny kid sidekick for him while he's hanging out in Tennessee, and the Mandarin becomes just another white guy in a business suit. It's not that I'm some purist about the comics, which are often quite terrible, but these alterations tend to come from people who are less imaginative than the comics creators, believing they can improve upon the original by throwing out the more outrageous and fantastic qualities that served to make the comics distinct.
Before the influence of movie studios, the comics industry used to practice the Jack Kirby Rule: a ridiculous premise is always better if realized with a cosmic roundhouse from some brute in a colorful costume. There's nothing particularly interesting about Tony Stark questioning his status as a superhero. It would, at least, be weird if he were doing this in a soliloquy while wearing his armor in the middle of a space battle, though. Otherwise, it's just some normal looking dude worrying about a problem that has no relevance to anything in life. So why would anyone want to sit through that?