Since you asked, you are about to find out how much I love my geese!
The only downside to my girls is that they OCCASIONALLY decide to nip at the chickens or ducks if someone is trying to eat food they believe to be theirs. On the other hand, a determined chicken who calls their bluff usually wins the spoils.
I don't think they are terribly loud and don't talk a lot anyway. I can get them to "answer" me by imitating one of the sounds they make when they converse with each other. (Yes, I may need more human friends).
They usually sound an alarm when they spot an eagle flying over, but certainly wouldn't protect any other the other birds should a predator attack.
Their wings are powerful. If you have to move a goose, make sure you have a firm grasp when you pin down their wings. An errant wing can result in a black eye -- and no one will believe how you got the shiner.
My geese aren't good at flying. When they get the zoomies, they will lift off the ground and "soar" down the length of the driveway, but rarely get more than a foot or two off the ground.
I have regular livestock fencing separating the yard from the sheep and goat pens. But, across the front -- which runs along a semi-busy paved road -- I have 3-foot-high woven wire fencing.
One of them once managed to get on the other side of the wire fence -- but she called out until I returned her to the side where her sister was. The geese are incredibly bonded to each other and will call out when they can't immediately see each other.
Mine are not people aggressive. However, they will get hissy when if I try to remove an egg before they are ready to wander off their nest. And, they protect each other's eggs.
I think geese are wonderful! Don't listen to those naysayers!