I finished my vacation last week. Back in Canada.
The biggest problem with the earlier closure at the park was INSANE wait times to get a ferry or monorail back to the ticket centre. When the park stays open even a little later, the traffic out is divided and smoothed out over a 2 hour period between 9:30 and 11:30. When it isn't the busy July crowd is crammed into a 1 hour window of mass exodus (9:30 - 10:30). So the crowd still takes until well after midnight to get out, but with EVERYONE just waiting outside the gates with nothing to do. Children screaming and crying and tired, seniors in discomfort.
We waited for the Ferry from 10:15 until 11:35 (only got out of the parking lot after Midnight). At one point we had to wait 30 minutes just for the electric boat thing from the GF and Ploy to travel by before ferries could start transporting again. Why wouldn't they take all of these things into consideration when deciding to close the park earlier at a busy time? I've been there at Christmas twice and it was NEVER this bad.
We had a great day at the MK, but it really was dampened by that exit. My mother and father (68 and 69) where so tired after standing around that long. They loved the fireworks and the castle projection show, but the exit is a magic killer. And the easy solution is one more hour of park time. I know many of you disagree with me (probably because you own stock and want more dividends

) but honestly it was the worst experience leaving I've ever had (and, like I said, I've been there at Christmas.)
C'est la vie! But that was my experience. Maybe others feel differently, and that is fine too. But Mid-July, in that heat and humidity, is not the time to have everyone exit at once.