I know this is an old thread but....
Opening day was nice and cold as mentioned, lots of willing mallards came in and we got 3, plus one black duck. Blew a few mallard shots and saw some Woodies in the decoys before shooting time.
Was out twice more in the same spot and everything was VERY educated very fast in my limited experience.
After late season opener the ducks continue to be very educated and wary of my spread. I've gotten some unwary teal and buffleheads to come in, and 1 gadwall, but the 5-7 mallard flocks laugh at me.