I love my Black Australorps! I have four of them and they are all laying nice little brown eggs now and are only 21 weeks old. They lay an egg almost every day, and get along well with the rest of the flock. Very glad I chose these to be the most well-represented breed of my flock. Also, they are jet black, with a green sheen, and I have been told that hawks hate crows and the Australorps look enough like crows or ravens that they will keep the hawks away from your flock. Another plus. I was also worried that they would over-heat in our occasional 100 degree temps because of their color, but mine seemed to breeze through the heat as well. Highly recommend this breed!
The original black Australorp was developed in Gatton not far from where I live. It can get to the top 40C's in summer here so heat should never be a problem for them. We get cold in winter too , no snow though but the seems to be able to adjust to any temp pretty well.