It does all come down to training. When I was young my relatives had bloodhounds on their farm. Those were the sweetest dogs!! I was very young at the time, like 4, and they never tried to bite me or anything. Of course b/c they are so big they sometimes don't know their own strength. That's the case with any large dog! They are usually some of the sweetest animals but have no clue how strong they are.
But if you get one, you will really enjoy him/her. They are really friendly dogs by nature. However, they will chase your cats!!! But they are hunting dogs so things like that tend to be in their nature!