I vote to drive to Disney World. I don't know where you are in the Midwest, but we drove there from Ohio several years ago and saved on plane fare. My boys, who at the time were just-turned-8 and almost 4 years old, loved Disney. But, we aren't a camping family so I would never buy a pop-up. I think there is something really special about a Disney vacation with young kids. There is definitely a window of time, in my mind, after which they have outgrown all the Magic Kingdom characters and such. It was important to me to go to Disney when my kids would still be excited about meeting Mickey Mouse, kwim? We plan to take them again when they are older, but it won't be as special as going when they were young.