I have an Old English Game Bird rooster (a grey). I got him as an adult bird. What I did was ask the seller for the nicest rooster he had because I have 5 kids. He led me to the grey. I have to say, it would not have been my first choice out of all the birds he had, BUT, I trusted the seller who had obviously had poultry for a long time.
The OEGB got the majestic name of Winchester and is about the nicest one ever. My kids can go right in and pick him up with very little fuss. And they like to carry him around like a pet. In any case, getting a rooster from an experienced seller, and letting him guide us in our choice, has worked out beautifully. I like the concept of buying a grown rooster, as you know what you will be getting-no surprises!
I agree, I think every breed has good and bad "apples", and that the treatment of the bird goes a long way in developing the character outcome of a bird.