I would not recommend ISA for anybody. Go astralorp or Rhode Island for good layers.
We have 3 australorps at the moment. I think Paul was thinking about the eggs, the australorps keep going broody. We've had ISA's for at least 10 years before we got this lot. I only had one broody in all that time. That was in the last lot we had Lucky was hatched from then, but she was the only one out of 12 eggs. I'm sure if it was a crow or the hen itself that ate the eggs and chicks. Lucky was rescued just as she was pipping. Hence the name Lucky. At the moment we have Andalusians, cochins bantam and normal, Araucanas, silkies, leghorn, light Sussex,
Spangled Hamburg's Australorps and a bantam australorps. But we only get at the most 6 eggs a day. But I think with the hot weather even ISA's won't lay everyday.