Kind of a no-win here. The Superman outfit looks goofy if worn in real life, but if they changed it the diehard fans would be flipping out. It looks ok, although I think the S should be bigger. In the end, it's still a guy who wears red panties over his tights.
After reading through the Death & Return of Superman comics recently, I keep thinking the costume of the Eradicator would have worked quite well here. If they jazzed up Batman's uniform in the movies, why not Supermans?
I don't know how to do spoiler tags, so read at your own risk: I haven't read the book, but it was an interesting movie. I had no idea what was coming, and when they all got caught in the "Food Store", I found that interesting.