First you need to find out if there are any regulations that prevent you from keeping a cockerel/rooster in your neighbourhood and if it will cause a noise nuisance to neighbours or even yourselves.
Pros...
1. You will be able to hatch your own fertile eggs which will make your flock self sustaining.... young pullets coming into lay as older birds decrease production and excess cockerels can be eaten if you can cope with that.
2. Roosters do usually stand guard whilst the girls are foraging and give a warning if there is a predator. This can be useful if you free range although it depends upon the stealth of the predator and the ability of the hens to heed the warning and escape in time if it is spotted.
3. Eye candy.... roosters can be very striking and attractive
4. They will usually round up the hens and make sure they all go to bed.
Cons..
1. Noisy... they can crow at all hours of the day and night.
2. An extra and unproductive mouth to feed.
3. They can be aggressive both to humans, other pets and even their hens sometimes if they are dominant and won't submit to him. Young roosters brought up with pullets of the same age can be a real pain when they hit adolescence. It's better to have an older established rooster with young hens or a young rooster with older hens who will put him in his place and teach him some manners before he is old enough and wise enough to take control.
4. They sometimes have a favourite hen that gets over mated and raw backed.
No real difference re the eggs apart from the fact that they can develop into chicks if they are incubated. Certainly no taste difference that I can discern and there is a miniscule visual difference although you have to be reasonably experienced to see it. Certainly the average person could not tell the difference.