I've got 4 Australorps and they are calm and friendly. 2 of them follow me around when I'm working in the yard and they let my kids pet them and pick them up. I love reading outside to their chattering. The other 2 are more timid, but I like my Ausrtalorps better then our last flock of Aracunas and Rhode Island Reds.
No experience with Cochins.
No experience with Cochins.