Two weeks away on any type of vacation is a very long time, but two weeks in Disney with a 1 and 4 year old is very very long and very very exhausting! I guess it depends if you are going to do the parks for all 2 weeks, or just hang out around the pool for one of the weeks. Also, no matter what, a 1 and 4 year old like being home, its really the only place they feel totally comfortable, ya know. Its like, you go to grandma and grandpas house for the day, and they love it, but at the end of the day, they are much happier and more themselves once they get home.
Don't get me wrong, I LOVE Disney and would live there if I could (wink wink) but you also have to think of how your kids will react to it. Also, with the four of you, I just always think the more room the better. Not that you'll be spending the whole trip (or much of it) in your room, but for when you are there, you want it to be comfortable.
Just a thought!