My perk is the hotels themselves. I don't want to stay in an ordinary hotel for a Disney vacation. I definitely don't want to stay in a rental house - on any vacation.
At Disney I want TOTAL IMMERSION!
I don't care who else gets EMH, I don't care if other hotels have bigger rooms, I don't care about free breakfasts - none of that matters to me at Disney. We don't go to Disney to see Orlando, we go to see Disney, end of story. And we will save for as long as takes for us to stay on-site. So we don't go but every few years, that's fine, plenty of places to visit in between, each vacation destination is great in itself.
Oh, and walking to/from Epcot is pretty awesome also.