Before I decided on ducks vs. chickens I also kept reading how hardy ducks are. That hasn't been my experience, although I know they aren't susceptible to some diseases that chickens are. In 9 months I've had splay leg, two cases of bumble foot, two hurt or sprained legs, eye infection, and a mystery skin disease that had me in the vet many times. There are lots of potential issues with ducks, just like chickens, so don't let that factor influence you too much.