My only experience with them was not good, I don't know why people choose such an unstable breed as a pet.
Here is the story, taken from another pit bull thread on this site:
I have a sister who her and her husband brought their dog that they were taking care of, to my parents house on Easter Sunday.
I was sitting in my parents living room when I here screaming coming from the kitchen, I run in there assuming the worst thinking it has one of the kids, to see this dog(who of-course has never done this before) latched onto my parents dog and will not let go. My brothers wife gets her kids out of the room and then we did everything we could to get it to let go, there was blood everywhere. We finally get it to release, I really wish that there was a gun nearby to shoot it in the head and get it over with, this is one of the most terrifying situations I've ever been in. My sister and her husband were so upset over the incident that they left.
Later I called them and told them that they are being pretty foolish for keeping a dog that is 8 years old without any kind of history, they said that they planned on keeping the dog, I also told them that most people will sue you if you dog viciously attacks there dog. They are acting like jackasses, it's people with this mentality that really scares me. I'm not sure what they are waiting for, I guess someone elses dog isn't enough, I guess they are waiting for it to hurt a human.
Looking back I wish I had just grabbed a knife and slit its throat, how awesome of a story would that be to tell people at the office the next day?