I can tell you, from MUCH experience with my English Setter, that they are the gentlest creatures you will find. Mine will allow my niece, who's 2 years old, to pet him and I know he wouldn't harm anyone. The only thing he gets aggressive towards is pheasants and basically any bird, plain and simple. Mine has hunted ducks with me as well.I don't hunt ducks in the typical areas(lakes etc.),but I would doubt if you could use them to retrieve from deep water. Mine is not afraid of water but would take a lot of training to be able to do that. I would say, just guessing, that GSPs are much better waterfowl dogs.

Setters are far more mild mannered than the GSPs and they have much nicer coats and are basically nicer to watch. They only complaint I have with them is that they are rather stubborn at times and do not retrieve easily. They shed like crazy as well, another consideration to keep in mind if you don't like hair on everything.

good luck with your choice. Get what you want. I don't think you'll be disapointed with the Setter though