Well, we went LAST mid-March (2004) and didn't feel it was crowded at all. Then we went this April (2005), 4/5-4/12... about 2 weeks after Easter and it was about the same, maybe a touch busier. At least that's how it felt. We had walk-ons for many rides and waits mostly 20 mins and under for those w/o FP available. Buses were not an issue, although there was some standing room only buses... mostly at obvious times though -- park opening/closing. THere were many times there were 10 or less on bus or monorail. If I could go next year, I'd go end of March to celebrate b-days and anniversary in our family... plus dh likes it when it's a bit cooler. It seems April is kind of the turning point month where things start to heat up and you start to notice the Florida humidity.