I have never had a polish or a blue so I can't say much about them, but...
My first bunny was a netherland dwarf when I was 7. I have had 5 netherland dwarfs over the years and they have been my best bunnies with younger kids. In my experience they are much more willing to be held than some of my other rabbits and have been calmer overall. They have been the least panicked when a small child picked them up and carried them around. Albeit they are not the cuddliest. Only two of the dwarfs I have had love to cuddle for an hour straight. They generally like to run around and I have had a bunny jump up between my dresser and the wall until he had gotten to the top of the 4 1/2 foot dresser all to get the birdseed I keep for my pigeon. Another spider-climbs his way up the wire to the top of his six foot hutch. They are mini ninjas.
In general my netherland dwarves have proven to be more intelligent than rabbits I have had from other breeds. For example my first bunny would go under our house and would come to me when I called for him. And my fuzzy netherland will stay in an area he can jump out of just because I tell him to.
That's been my experience since netherland dwarves. So in my experience yes they are hyper and a little melodramatic at times but they have been extremely sweet.
