I think I've posted about my experience with the few roosters I had as nauseum, but since this is the topic of the week, I figure it's the right place to post
The roosters I've had were all by accident. I didn't see any benefits of having roosters whatsoever. My hens weren't very fond of either of them and some definitely hated them altogether. Even if there were more than enough hens per roosters, there were always the favorites with bare backs. There was one rooster that constantly chased this one hen not to mate with her, but to hurt her. It got so bad that he wouldn't let her into the coop at times. All of my roosters crowed loudly and often. And unfortunately, all of them eventually became human aggressive. They didn't do very well in keeping the flock together, as the hens went wherever they wanted despite the rooster calling them. I think this made some of them even angrier for being ignored.
As for predators, I have a problem with birds of prey and there was no difference in the losses I had having roosters or not. Actually, the roosters never got caught because they ran away faster.
Breed wise, I had 2 Orpingtons, 1 bantam LF cross and 1 silver leghorn. All turned aggressive beginning at 5 months of age, so I don't know that the breed makes any difference.
I never treated them as pets and I don't have the habit of holding the chickens. Nobody in my family did anything to provoke them but like clockwork, they turned aggressive at this age.
The only pro I can think of about having roosters in my particular situation is their beauty. They do add beauty to a flock.
In situations where a person is raising for meat and/or wants to add chicks to the flock, raising roosters is great. Most can go to the freezer before they become aggressive and the one selected for breeding can wait a little longer before joining the others.
I'm not trying to discourage people from having roosters, as I've heard many stories of well behaved ones. It just didn't happen to me or any of my friends' backyard flocks.
I think it would be nice to have a well behaved rooster who did his job well, but after my experience, I feel I'm done. My hens are much happier without a rooster and I don't see any tension in my flock.