on the LED stuff, it was simply a matter of longevity, maintenance, and mainly energy savings. on cinderella's castle at magic kingdom, they use fisherman's nets with led mini's zip tied to them and fully "wrap" the entire surface of the castle. the nets and wires are painted to match the color of the castle. energy usage is impressive. even with LED, the castle still uses 2 240 volt 40 amp circuits, or two clothes dryers. I would equate that to 20 amp 120 volt circuits, and that is 8, 20 amp circuits. still a lot of juice- but on incandescant, they USED to use 9 times that, or 18, 40 amp 240 volt circuits, just to run the castle.
I did not get a chance to see the castle or anything with the seasonal lighting on it, just the permanant stuff. kinda hard to get to disney at Christmas time when you run a Christmas biz.