Actually, I have successfully bred my CX hens to my CX roo, and gotten great meat birds, that are a little harder then CX's. (go to Cornish rock cross/black australorp thread for more info!)
I have Black Australorp Cornish rock cross eggs in my incubator right now!I can't wait to see what hatches! I restricted my cornish rock cross hens food so they wouldn't get so big and they started laying, so I put some eggs in my incubator!
Actually, I'm trying this out! I crossed my cornish rock x hens with my black austrolorp rooster and am collecting eggs from my cornish rock x hens everyday, and am going to try to hatch them out! hoping for the best!!!