We had also heard about the MK being crowded, so that's why we avoided it. Sorcery in the Sky started at 9:00 pm and Illuminations at 10:00. We made it with a few minutes to spare.
Afterwards we drove over to the MK just to say we'd been there on July 4th. There were tons of people coming out - the lines for the monorail were insane. Hardly anyone was going in, though! LOL Of course, the fireworks and parade were over, but we just rode a few rides and enjoyed the atmosphere. On the tram out to our car at closing time the driver said that the MK had closed for a few hours that day (I think he said about 1:00 and reopened at 4:00?) I'm not exactly sure of the times.