I have never owned a pit myself and don't know too much about them other than what I've read or heard on the tv. None of which has been good. However, I do believe that as long as it hasn't been irresponsibly bred (inbred) and the way that it is raised and trained makes all the difference in the world. That being said, unfortunately many of them have been inbred, improperly raised and trained which has led to all of the problems with this breed.
My only personal contact with a pit is with my neighbor's. She keeps him in the house other than for a few minutes to potty several times a day. He is a gentle oversized baby.
My daughter's one girlfriend owned a rottie, who although huge, was also the dumbest thing I ever met. He too was sweet.
Both these dogs were housedogs and were AKC which I'm sure helped make a difference too.
But, although these big guys were sweet, I would still not let my little one unattended near them as they can sometimes instigate defensive behaviors from the big guys through their barking and nipping. That is simply a dog thing, not that the dog itself is necessarily bad. So, that's being responsible on both sides.
BUT, unfortunately not all of these big dogs are like this. So yes, until I knew otherwise, I too would be concerned and nervous about a pit or a rottie next door to me.
People should not be allowed to own one of these dogs if they can't properly raise, train and control them.