Well I have 12 (so far) and the breakdown is 4 Red Star, 3 Buff Orp, 3 Langhans, and 2 Australorps.
Despite all the good things I read about Australorps thus far they are my least favorite of the four. They are mean to the other chickens but when my Pyrenees confronted the flock for the first time (pup is only 8 weeks old and we are trying to teach her to protect the chickens) it was the Red Star (normally harassed by the Australorps) that stepped up to back the puppy down with the puffed neck and head feathers doing the "You want a piece of me?" act in pups face.
I was impressed by the Red Star and would wish for more if I could roll back time and swap the Lorps for Red Stars it would be a no-brainer.
The Langshans are good strong looking birds with great posture - I like them a lot but think they learned some behavioral downside stuff from the Australorps like not being nice to other birds and not getting back in their tractor when the time comes.