Pros: Friendly, tame, quiet. Get very big.
Cons: Eat like pigs, need nutritional needs met. Get very big.
They make great pets, keep in mind though they will be heavier than a lot of other ducks. Are not good foragers. I find giving them some extra vitamins help. I had some leg problems with them as ducklings, as they grow so big and so fast, so I made sure they got extra niacin in the form of brewer's yeast or crushed niacin from the drugstore (not the nonflushing kind). They all eat out of my hand!