I've owned pitbulls my whole life and love the breed. That being said the whole nanny dog, harmless lover thing is a meme, and hurtful to the breed, as it convinces many who shouldnt get one to get one.
They require a dominant owner, who does not lose their temper easily, and will not be scared off by growling, or aggression.
They need an oulet for their energy and aggression also, boar hunting, a tire to grab and swing on, lots of rough exercise etc.
They are often not friendly with other animals, my current one only gets along with other pits, or mastiff type breeds, and is overly aggressive to other types of dogs, provoking them to attack her, then fighting back.
They arent a dog you take to the dog park, or leave a kid with.
If it gets into a fight, dont expect to easily break up, or not get bit doing so. My old pair sometimes got to out of hand, and I have scars from splitting them up.
They are an excellent hiking companion on empty, far out trails, or boar hunting dog.
Not a good first dog, or a good city dog, they need room to run, and a fence.