Just remember...It's FREE!
If you only go there for a meal...go there! The architecture, the restaurants, the very strange (yet cool Apple store, the clock above the information desk in the center - everything can wow you.
My advice, take a few hours - head in, grab a few pictures of the clock (Ever seen Madagascar? It's the one Melman the Giraffe ends up with stuck on his head!) and get the big American flag in the background. Then wander around the shops, including the very cool Apple store. Finish off be heading the lower levels and grab a piece of Cheesecake at Junior's.
Oh, and Skip the audio tour, there's too much boring audio commentary available in New York, enjoy the scenery and magic - don't be such a tourist!