All this depends on what the grower wants. Does the grower want a true-breeding or dual-purpose chicken? Does the grower want strong foragers?
I’ll admit that I’m playing with a very small test group of 4 Cornish X . They have been fun to raise, especially with some restricted feeding and “flying for food.” They have great personalities and are just nice chickens overall. It’s so fun to see them fly for food in the morning and evening.
They’re nowhere near processing weight mostly because I’m deliberately slowing them down to see whether I can get a hen to reach laying age.