I've done 21 CX, six 3m broilers (Ginger Broilers), a year old production red and a year old GB, and have more scheduled for this spring/summer. I've found that what the roo eats and lives in determines the smell of the meat encountered while processing. Different meatbird food has different...
Anything over 5 months I pressure cook it just to be sure it will be tender. Year old roosters make the best flavored chicken soup and BBQ and are always tender after 20 minutes at 15 lbs pressure, with the canner half filled with water and all the veggies for chicken soup.