We were not there for spring break 2011, but we were for 08,09 and 10 (and will be for 12). These trips have been before and after EAster. I can tell you that MK did open at 7AM for EMH every day those weeks. I'd seen the sun set at MK, but seeing the sun come up there is awesome. And using those hours at MK is crucial because by noon it is very, very crowded. Some day when I am done teaching I'll finally see what the parks are like when kids are IN school!
I don't remember any other details, but we always get there at open and do the big rides with fastpasses, and we are fine.
Daisyx3