My two ducks are both incredibly friendly...the Campbell is extra friendly and will quite happily sit in the house, wearing one of Netties nappies, on someones lap having a stroke. The runner, while very friendly doesn't like being in a lap much. Fine being picked up, fine being stroked and having her neck scratched, but just not in your lap.
In saying that there was a time when the Campbell went from thinking you were the best thing since sliced bread to you're going to eat her...she was about 10 weeks old and it lasted until she started laying at around 24 weeks. As soon as she started laying she became docile and even friendlier than before.
They both know their name and reply back to you when you call them.
I found that they both respond to stroke = treat....for extra bonding you can always run them a nice warm bath for them and feed them meal worms while they relax. Mine love that.
Sometimes they are too friendly like when you're trying to dig the garden and you spend 90% of the time chasing them away so they don't get sliced in two by the spade. the runner has no fear!
They are still ducks and don't like strangers...there's no way either will let a random person stroke them in the garden...which is very different to my Bantam Cochin...where any random lap is a potential target...she stalks people until they sit down then, squark, chicken in your lap regardless if you wanted her or not.
Woka