My two year old 75 lb female is an incredible dog...
I've trained hunting dogs, pointers, and retrievers for years. Every pit bull I've ever encountered is an incredible dog. The one I have is an incredible dog. But, they are also dangerous dogs. They can hurt you without meaning to. And, one day, you will do something that dog won't like, and from that day on, it will be the boss. And, unless you know how to physically subdue and control a dog like that, you will have a big problem. The one I have has never been abused, or mistreated in any way. But, once he got to be about 5 years old, his attitude completely changed. It's like he has no patience for anything. It's his way, or else.
I take him to the vet once a year, and when he sees me coming with the muzzle, the fight is on. I have to wear the gloves and arm protection and literally bulldog him down to the ground to get the muzzle on him. From the time I put him in the car/truck to the time I get him home, he is literally drooling and foaming at the mouth he's so mad. Once we get to the vet, he has to be drugged to be examined and have his nails clipped.
All pit bulls require a helluvalot of exercise. Most don't get it, and it can make them irritable. The one I have plays well with other dogs, but he plays rough. I have to put him out in the yard to play with two German Short-hair pointers that outweigh him by 20 pounds. He will injure a smaller dog (and you) without meaning to. Anytime he even nips you, he draws blood. That's what makes pits dangerous. They can hurt you without trying. And, if/when the day comes they are trying to hurt you, you better be ready.