Difference between goose down and duck down
Geese down clusters are usually much larger and fluffier than that of ducks. As a result, goose down will have much better insulation performance.
Secondly, because of the diversity of diet, duck down can emit some special smell if not cleaned thoroughly. This will never occur on goose down.
In addition, it usually takes much longer time to breed geese than ducks. Thus the price of duck down is very competitive than goose down.