I have a pit bull in my pack of 7 pound puppies, they range from Black Lab and English Mastiff to Boxer and Boarder collie. Billy The Fearless Bear Hunter (the pit bull) is one of the gentlest dogs I have ever had in my family.
Yes; he does hunt the bears, he is just smart enough not to catch them. Also thinks he is a lap dog.
I have two of yours in one, English Mastiff + Black Lab = Mastador. We go to the dog park often and interact with LOTS of Pits and in six years there have only been a handful of fights that were anywhere near serious and of those only a couple involved Pits brought by cholos who mistreated them. I have not met a Pit that has been anything but sweet, I know they are out there because of man, but hey my grandson sleeps with one and God help the person that tries to hurt him.