To us a regular bull is someone who we respect and who respects us. He is a man who puts in the effort to get to know us, works out what we want and goes out of his way to deliver it.
Once he had done the above he will be exclusive to us. Besides me, he will be the only man my wife spreads her legs for.
The advantage is that he has learned how to please us and us how to please him. A relationship can be formed and comfortable companionship outside the bedroom can be achieved as well as trust in the bedroom.
Basically he is more than just a cock, he is also a friend.