All 3 of those are beautiful.
I have Swedish from two different sources., One group is badly mismarked and very high strung. The other batch are lovely and very annoyingly curious. It's almost impossible to clean their brooder because they are crawling all over my arms and sitting on the trays that I am trying to remove from the brooder. They jump on the paper towels and take a ride as I am trying to spread them out.
There should be no difference between Black and Blue Swedish. They are the same ducks hatched in the same clutch, just a different color.
All ducks are nice. There is going to be a lot of difference in the personalities based upon who the breeder was and whether or not they breed for temperament.