Location and conditions are very important. I've found this out from 30 years of hunting ducks also on crowded public land.
Early and midseason ducks are best by me with a couple of soft sequences.
Late season and migrators are the best to work and most enjoyable to see cupped wings but you still need to know what your doing. Your cadence tone ect are all important.
Over calling = bad - anytime of the year.
