When comparing goose down and duck down of similar quality, i.e. the same fill power (loft), there is little physical difference between the two. They both provide similar levels of insulation and maintain their loft and warmth for years when properly cared for. However, there are still a couple of differences to consider.
The first difference, which could potentially affect the user experience, is the possibility of lingering odor from duck down. Duck down is inherently more odorous than goose down. Even though the down treatment and sanitizing processes remove most of this odor, people who have an acute olfactory sense may still be able to notice the difference. For most of us though, including us at Linens Delight, the smell is not noticeable.
The second difference is the availability of high fill power down. To achieve a high fill power (usually >750 loft), a high percentage of large down clusters (also known as plumules) is required. Since geese are in general physically larger than ducks, it is only possible to harvest a sufficient quantity of large down clusters from geese to produce high-end down at scale. Therefore, high-end down products are mostly dependent on goose down, resulting in goose down being more premium and expensive than duck down. You can find low-grade goose down and high-grade duck down, but on average, goose down clusters are larger and loftier. The duck down products we offer range from 600 loft to 800 loft and the goose down products range from 600 loft to 950 loft.