It also depends on the dogs nature. I have had Boerboel dogs and Bull Mastiffs and actually look at Rottweilers and Dobermanns as pussies. I think it all depends on how they are bred as mine are all different and one is placid, but can turn immediately. The dogs I have respect for and not fear are any dog that can lock it's jaw when it bites and there are only a select few. I wanted a Cane Corso but the family voted me down.