I"ve been there several times and that is where I proposed to my wife. The food portions are small, everything is ala carte and it is expensive but very good. You cant beat the view though and the dining room spins while you are eating. I cant remember how long it takes to make 1 revolutuion but it's slow, like once and hour.
If you don't eat there it costs something like $12 to ride the elevator to the viewing deck, otherwise if you are eating it's free.
Don't forget to by the "Weedle on the Needle" book from the gift shop.