That and disney starts to break out all the christmas stuff, including decorations, parades....all of the normal stuff. They do that right before Thanksgiving, and a lot of people flock to it. I would go the first couple weeks of November, but be warned.....not busy for disney=packed for a lot of different parks.
I agree with the NOT staying onsite at disney. Not worth it. Busses are always crowded, and if you get up early you can usually make it through a park before 2, and start hitting some rides again.
Universal, definately worth it. The parks are five minutes away by boat, the express is nice to have...that way you can sleep in after stumbling back to your room from CityWalk.