My neighbor two houses down the road from me has a flock of guinea fowl. They are a big traffic nuisance. They have no concept of the danger of the road, and the whole flock will suddenly strut across in front of my car. I have had to slam on my brakes several times to avoid hitting them.
This is probably the only issue I have with people letting guinea fowl roam free around their yards. The noises they make do not bother me, and I wouldn’t even mind if they wandered into my yard to chew on some insects. I just hate having to watch so closely for them whenever I drive past his house.