We've been a couple of times on the 4th, and other than New Year's Eve, the evening was the most crowded we'd ever seen MK. One year we watched the 4th of July fireworks on the 3rd and went to DHS on the 4th. Honestly, I think DHS's fireworks/music show was the best of the bunch. EPCOT's is just an extended Illuminations, with a tribute show tacked on at the end. All are good, but be ready for standing room only in MK.