The thing that's tricky about September is that they only offer MSEP on a few select nights of the week, so those nights are REALLY busy. I've never been at other times of the year, so I guess I can't really compare. But we go in Sept every year, and it's always felt very uncrowded except for this one particular experience. And the times we've tried to see it have been craziness. We tried staking out a spot 30 minutes in advance last time and everything was full on main street. We should have gone back to frontierland, but crowds were too insane for us to make it back there from the entrance. So we just watched with semi-obstructed views. It was a bit of a disappointment.