We just got back from being there Wed thru Sunday.
DL was very busy on the days we went...Thursday and Saturday. However, we used EE on Thursday and found the crowds to be really light until 10am or so. They gradually got heavier until we left around 1pm after lunch. By then, the park was packed.
We came back for the late parade and fireworks arriving about 20 minutes before the parade. We got a spot at the top of the hub (even got a bench to sit on!) with no problems. We watched the parade, then just kept our spot until the fireworks. After that, we waited 20 minutes or so for the crowd to thin out and rode quite a few rides before leaving the park around 11pm.
On Saturday we only went in to go to ToonTown Morning Madness, happened on to Space Mountain being open and then watched the Snow White show using our preferred seating passes and got the heck out of there. It was a madhouse!
I would suggest that you not try and navigate the rush of people leaving after the parades or fireworks. Sit back and people watch for 20 minutes and it's much easier to move around!
DCA on the other hand, never seemed crowded even when it was!
Yes, DL is very busy but if you take advantage of fastpasses, EE and the late closings it really isn't too bad at all.