Just got back. We arrived on the 4th and MK was very, very crowded, which surprised us, but other parks that first week weren't as bad. The Tuesday after the marathon, the crowds dropped off, and we thought the rest of this past week was very doable, with the parks being full, but not crazy.
Marathon weekend did hit a glitch this year because they had to cancel the Saturday race due to weather. They then offered those folks a spot in the Sunday race, so I think there were more people coming to cheer for their family members on Sunday. Like fools, we got on a very early bus to get to MK at opening, only to be stuck on that (very overcrowded) bus for over an hour, hoping to make it to our FP for 7DMT. We did make it in time - but the ride was down . . . hahaha, best laid plans, right???? Moral of the story - just sleep in on that Sunday morning, and go to the parks later.