I have kept both. Hens may have a harder time throwing eggs with extra fat/heat. Males tend to over heat during late summer breeding. I keep several roosters . If you end the best one you will never know. Some may die early, some may never be interested in breeding-just eating. I have Dark Cornish roosters over Cornish Cross hens first generation. Second generation I kept back a 50/50 rooster over dark cornish hens. Back and forth.