I discovered girls at a pretty early age (though, sadly, it took a while for them to discover me). I was also crushing on the cuties, especially the Disney ones. So were I your young son, eating in CRT would suh-weet. But if they're not into the ladies yet, you might want to at least consider some sort of compromise where they get to decide where to have breakfast the next day, or some other meal.
They'll at least probably dig the view, eating in the MK, stuff like that. Presentation is important, too. Tell them a little white lie, that you always heard HOW HARD it is to get a reservation in the castle, but that you always heard it was cool, and the day of your reservation, pretend that you're trying to get in. THis way, they feel like they had a bout of good luck and might be apt to appreciate it a little more.
Oh, yeah, I'm all about lieing to kids...