I'm afraid they won't last here, but we may try them eventually. We may also someday reduck. We're just trying to enjoy being duck free for now. Right now I can't even let the chickens free range without them being killed. Not sure ducks would be able to do proper "work" under confinement for their own protection. My concerns are the same for guineas.
I've considered a LDG to help on the hawk/coyte/weasel/fisher/bear/potential unverified mountain lions front, which would let de-bugging animals like chickens, ducks, and guineas work uneaten. I'm willing to bet just having a big dog walking or laying around the yard will make attacking things wary, but I can't afford to put up a perimeter fence, so I'm going to guess they're a bad idea. I've only got the 100 foot pen, the barn pens, and the chicken pen enclosed, and I get the impression that putting in real posts here is going to take heavy machinery, experience, and probably a tractor. I'd probably find someone who does it for a living here and hire out, but not right now. Maybe when the house is paid off in a few years. Then I'll REALLY never want to move again.
So yeah, that's why I'm okay with no ducks or guineas. The ducks can't roam, we can't keep protection for them at this point, so no ducks.