Really free-range poultry (backyard chicken, rather than chicken grown in a factory with a tiny yard just enough to satisfy free range regulations) is like you say, tough, stringy, full of muscle, with normal-sized breasts and its meat is dark. It's no good for roasting because you really have to boil it for a couple of hours at least in order to get it to the point it's edible. I made the mistake once to only cook a hen for half an hour, like I'd do for supermarket chicken and I spent the night chewing until my jaws ached (I didn't want to throw it out. Poor bird died so I could eat it; so I ate it).

That said, real-free-range chicken makes the most unbelievably godly soup. They have this amazing yellow fat and their skin is thick with it, so they make a really thick broth. Just add a few vegetables, a bit of celery, some carrots, potatoes, and you don't even need rice or anything else to thicken it. I suspect it's that kind of chicken that people mean when they say that chicken soup is good for you when you're sick. It's the kind of soup that could raise the dead.

Edit - I forgot about the bones. Real free range chicken bones are hard. You can't just snap them between your fingers. Well I can't anyway. They're like real bones. Amaze!