There is absolutely no cons to a d'uccle. You can hug them and squeeze them and call them George....
Seriously, I free range mine and they run any meat off themselves looking for bugs. They walk funny because they have HUGE foot feathers, that always make them look like they are wearing footie pajamas. The foot feathers do break off, but not all the way. They are super friendly and super curious. They fly when they need to, put themselves back into their coop at night so that you can lock it after them and they get along with other birds. They go broody when they want to be left alone by the boys.
My four month old chase away the crows that come down to eat their food. And they are not SO small that any rapture can come and get them. They lay pretty good, crow all day but not alot. I would make sure you put them in a fenced yard to keep dogs away. Cat's tend to leave them alone after they get larger.
Hope that helps.
Did I say they are cute and cuddly?