Call me CrAzY, but as a Chef my 12 wk old Delaware carcass looks great to me.
When I see the short-legged, crazy young yet overgrown, plump watery breasted cornish x carcasses in the grocery store, with the pale white skin and the flavorless fat...then I think "Wow what a sorry looking carcass". I think my 2.7 lb grass fed free range heritage breed yellow skinned long legged carcass looks waaaaaaayyy better than...any other chicken carcass I've seen.
The reason it looks like a carcass from the early 20th century before the broiler industry took over is because it is a Delaware carcass. Delawares were the broiler of choice in the Delmarva Peninsula from the early 1940's through the mid 1950's (when cornish crosses took over), and as the Delmarva Peninsula grew chicken for the east coast the Delaware was the choice for chicken on American dinner tables during that time period.
https://en.wikipedia.org/wiki/Delaware_chicken#History
This is a lot of the reason I am growing out these birds, is to taste a part of American history that is not otherwise available and has nearly been forgotten. I think that the sensory experiences of raising and eating traditional foods provide a vital connection with what it means to be human, and the carcass of a heritage breed chicken processes, looks, and tastes much different from 21st century commodity chicken.
Also, unlike most chicken consumers, I don't see chicken and think "breast meat", I much prefer the darker meat of the legs and thighs. The Orpingtons are supposed to be heavy legged (though with this hatchery batch I am having my doubts!) so I am hoping to wind up with a chicken that doesn't necessarily have such a large breast but compensates in larger legs and thighs.
When I introduce new genetics next season I am leaning towards Cornish (because...of course) and Brahma (the most popular meat bird in America during the turn of the 20th century) and maybe even some silkies because I love black chicken. Asil look...crazy...fun looking chicken, but not the meatiest looking birds, not the best egg layers, and with the reputation for aggression probably not best around the kids...