I've still got the scars on my arm from when a bull mastiff bit me, a confirmed dog-lover, in 1994. All I did was knock on its door and speak to its master's son and it tried to kill me.
They are beautiful dogs (see, I still don't hold it against the breed) but please take care over the temperament of any potential mate for your bitch. With those powerful jaws if my biter had got a small child, instead of me, it could well have been a fatality.