I own a female pit bull, named Sheba...I raised her with TLC since she was 5 weeks old, and she is a genuine sweetheart, and a she is also a good watch dog/great protector of her master!
As for the MEAN pit bulls, most importantly is the way they are breed/their bloodlines, and then how they are raised, and treated.
It is such a shame...I have 8 adorable, loving, and sweet puppies of hers, 8 weeks old...and I am having a hard time finding them good homes~ people just don't want to "take the chance" of raising a pit bull...and I can't get renters insurance either, because I own a pit bull! PIT BULLS got a BAD RAP!