Weeeelll. You asked for it.
My loopy neighbour had two presa pups when we first moved here. She kept one and the other went to live with the daughter. Both are incredibly sweet natured dogs, great with children but protective of their boundaries towards strangers and other dogs.
The two sisters when together will occasionally have an all out bitch-fest but it sounds and looks much worse than it is. It tends to last a minute or two and then it's over - everybody as they were, no skin broken.
Elfa recently had to cope with the introduction of a poodle puppy. She was relatively cool about it but until today is not at all warm with the little dog. But then, neither am I. It's spoiled rotten, mama's baby, whereas this huge beautiful beast cannot be picked up and snuggled.
Elfa visits my house, She ignores my cats, sits politely with Skye for treats and knocks over everything in sight with her tail. I haven't ever had to tail-proof my house as Skye had hers docked before I ever got her. Now when Elfa drops by I have to run around picking things out her way.
My personal experience of Presas, right here in the Canaries where they originated, is that they are powerful, impressive dogs, deeply loyal, affectionate and protective. From those I've met I see that they can be reserved with strangers, though Elfa if someone is invited into her house as opposed to loitering in 'her' park, will greet everybody with a lethally whipping tail and a present. Usually a shoe which she presents to you at the door.
Elfa is a cracking dog and I would have her myself in a red hot minute if the neighbour ever decided to part with her.