They are nice to look at. The good ones will watch over the hens and call them over to food or warn them of danger. And of course if you want an alarm permanently set for 3:30a.m. there's that too. If nothing else, they taste good, and it's a lot easier to process a mean roo than a sweet hen.
Security can be a pretty big benefit. A single dog ripped through our entire flock once save one pullet. While your hens scatter and hide the rooster can meet the predator and at the very least sacrifice himself for his girls. Kind of sad, but then you don't lose your layers. We can't have roosters due to noise ordinances, but I personally love to hear a rooster crow.....and they're pretty! I personally think Easter egger and Ameracauna roosters are especially gorgeous.
I have 3 roos and I really love them. One I have specifically is super valuable to me... I think he's a sexlink. Not only does he watch over the girls, but he absolutely will not tolerate any fighting, so he keeps peace in the flock. He is really good with his girls - very patient and very gentlemanly with them, and I have noticed that they all stick together better since I put him in with them and they also seem much happier to BE together. Having him in with my girls has completely changed the dynamics of their behavior. They are just more content over all. He's 4 this year and I was really worried when he went lame on me last week...but he's okay now. I hope he will stay with me for several more years, and maybe teach another roo later on how to be just like him!
My Favorelle roo is basically worthless as a roo other than to fertilize eggs. He's pretty, but he crows a lot and he has no sense about looking after the girls I have with him. I keep him only as a breeder for meat chickens.
I have 2 Silver Sebright brats but they are adorable.
and I have 2 big White Rock roos named Kurt and Kyle. When I give their flock treats I start by giving them directly to Kurt (he's the dominant one) and then some to Kyle. They make the treat sound and give them to the hens. It's my way of saying "I'm in charge but you get to do the rooster thing." They don't like being held or petted but they tolerate it.
Now if any of them turn mean they will go off to freezer camp post haste.