We love our Guinea Fowl. Since we got them, we no longer find ticks, stink bugs, grasshoppers, crickets or any bugs. We've also seen them catch and eat mice, frogs and small snakes. The whole flock will attack a large snake and drive it off. They found a Copperhead down at our shop a few weeks ago and harassed it forever before it found a hole to crawl into.
They pick potato bugs and tomato worms for me in my garden and don't scratch and eat the produce like chickens do. They only take a bite here and there. They have one place they dust bathe in and that's fine, they can have it.
They can be noisy, but if they are causing a ruckus, it's worth your while to go have a look, cause it's usually a predator of some sort. Ours had the neighbors cat surrounded a few days ago and I bet he never comes back.
They are fearless and very curious. Ours are quite tame compared to most and some will eat from our hand. Ones we bought from other people seem much more wild, but we do spend a lot of time with ours from keet age on. We have always had a plastic jar with some rocks in it that we shake whenever we feed them. When they hear that sound, no matter where they are on the property, they come running and flying in to feed.
They also go in the coop with the chickens every night. Earlier this spring they were laying eggs in the coop, but recently they started hiding them. No matter, just watch for the cock about 10am - noon. He'll be standing by himself and the hen will be on a nest nearby. The only ones we have trouble with are young juvenile males. They will chase our juvenile roos and pullets sometimes and pull some feathers. Trying to prove themselves, I guess. The cocks will also fight for hens in the spring, but we don't interfere with that, just survival of the fittest rule there. They usually mate for the season and sometimes for life.
Hope this helps. We have 9 colors of Guinea Fowl now and always have some for sale at various ages and eggs as well.