We've gone the last week of April for the last two years and did not have a problem with crowds. It is only really crowded on the years Easter falls late. When Easter is in March or the first part of April, late April is a wonderful time to go. So you should have no problems with crowds this year. The only negative about the end of April are the Grad Nights. They do not really effect the crowd level from what we could tell, but the MK closes early on those nights.