Bunny-hopping. Easily. No diff, etc. Why go A -> B when you can go:
A left right left right, land just right on the crate to reach for the high ledge, tap crouch to be sure, pop off, pace urself for the door -> B.
still in mid air turn to the door muck, make two circles like a speed demon, trip, fight normally, start to build up your acceleration from the beginning and scurry away