We were here during the college spring break and it was fairly crowded then. Remember that the local kids in Florida have spring breaks that coincides with the college spring breaks, since they return to school in early August, instead of last August or early September, so that feeds into it.
The hours are usually somewhat extended, but not to the extent of summer. MGM, and MK were open until 8 pm, and Epcot had its normal hours. Because daylight savings time hadn't kicked in, AK closed at 5 pm. Hours at MK were extended if crowds warrented it.
Usually the college aged kids are very well behaved, so if you are basing your decision on them, and not the crowds, then you should go. If you are only basing it on the crowds, you should still go, but plan out everything, so you will get the most bang for your buck, so to speak. Use Early entry, use fastpasses, if you aren't using EE, then go to the parks that had it the day before, and arrive at the gates 30 minutes prior to opening. Plan your meals at off times or after the parks close so you aren't eating at prime touring times, and don't have to spend time waiting for your seating. Make those Priority seating, as some restaurants don't accept walk ups!~
Hope to see you during your Spring Break!