Just wanted to give you a heads up. If you have larger turtles in your pond be careful. I have seen turtles snatch baby ducks under for a meal! A DNR guy told me about it....and I did not believe him. That is until I seen it first hand!
As for ducks compared to geese. I really do not mind the ducks so much. The geese on the other hand can be quite messy if you get a lot of wild ones come in!