So True.
I think whats made all of these comic book movies popular is that they ARE believable . For example -
The Dark Knight
The X-men series
Captain America
Iron Man
All of these movies had a realistic take on the hero , but that didn't affect the overall movie. Captain America's costume in the film is based off of the "Ultimate Avengers" series , which makes the costume more believable . This new Superman Costume would NOT pass in the real world. I think what makes a good ,believable costume , while still making it look like the character, is crossing it over too the real world.