Their are many pros to a rooster. They are beautiful, if your hen goes broody, or you have an incubator, you can replenish your flock, they protect the hens, and I love the sound of crowing (that may be a con for some people, I guess).
The biggest con for me is that they can tough on the hens' feathers. I have 1 rooster to 11 hens, but my rooster seems to have 3 favorite hens that bear the brunt of his affections, and those poor girls are completely bald on their backs by the end of summer. It regrows with the molt, but it doesn't look like much fun. I keep hoping he'll get less randy as he ages.
The other con is that the protectiveness can be a nuisance. Duke is completely fine with me or anyone else in his yard, cleaning the coop, etc. But if you pick up a hen and they squawk, it gets uncomfortable. I've only been pecked once (never flogged), as he usually figures out I'm not really hurting his hen, but having him tear across the yard and approach me aggressively if I'm handling a hen isn't a ton of fun. I've solved this my separating either Duke, or the hen I want to examine, the the coop, but it's an extra step.
All that being said, the pros outweigh the cons for me.