I would agree that a duck's personality is largely influenced by how you raise and treat them, as well as by their other life experiences and their flock members. Plus, each duck is an individual, just like people are. For example @Quatie has a fearless dominant khaki. Where my khaki campbell was more shy and reserved, letting all the other ducks boss her around and eat first. And my welsh harlequin is my bravest! My crested pekin is awesome, however her health issues have dug me into an early grave with worry and cost me a fortune in veterinary expenses - so I'm not sure I can recommend that breed. I also had a cayuga before and she was delightful, too. I guess I enjoy having a variety!
We keep a small flock of silver Appleyard ducks, and they are very much part of our garden plan. They have devoured our slug and snail populations, and their bedding/manure is great for our raised beds. We get, on average, 250 eggs per year per hen. Ours are remarkably friendly (perhaps even adorable little beggars at times), and they come when called. They are a large breed duck.