Ahh - yeah - the Gadwall here are really sweet. I've never eaten Harlequin or Scoters or any salt water ducks.
The Gadwall are about 98% or higher, insectivorous & vegetarian, whereas Mallards, 96% veggies.
The mallards around here get into washed up spawned out salmon - retch!
When they are in the grain fields they're good, but once they get into the salmon on the Fraser river - yikes.
I still prefer Gadwall over any Mallard.