Haha, while I am one of those waiting for a spot I'm going to have to really disagree with your recommendation, in good spirit though it may be. Neurone, find out which one is best for you. I've heard from most people that NDSEG is more prestigious (the academic definition of which eludes me to this day). I would go with NDSEG over NSF but that's only based on the meager amount that I know of the differences between the two. I have also seen the 'deferred to accept _____' and it seems to be effective in getting across the 'prestige' of getting the award so no matter what you're not losing that.
Good luck deciding!