i think that both breeds are good dogs for the job.any good bred boerboel or presa will do his job traind or not. years of selective breeding makes them do it naturally. for example my 3 year old bb is kept as pet he is friendly to everyone and social to other dogs too. if i say its ok he is fine with that and stay relaxed.but if someone screams at me or make strange movements he is ready to protect me in less then a second.when i am home you can just walk in and he maybe like you or not but he stays relax