My Mom had several Muscovy ducks when I was a kid. We used to eat them all the time. I never noticed any difference from chicken eggs. But of course I was about 10, so I wasn't overly concerned with what I ate!
We buy a dozen of duck eggs every two months or so to make salted eggs. They are nice to eat and many ways to prepare them. I tried making century egg but have not got full success yet. Chicken eggs can be used to make these two kinds of egg but duck eggs is preferred. Yummy!!!