Bully Kutta owner, so let me take the harder one.
What people get wrong: that it is an aggressive breed. It is not. It is a serious breed, which is a different thing — enormous, powerful, independent-minded, and bred for generations to make its own decisions without asking a human. That is fine in the right hands and genuinely dangerous in the wrong ones.
What is actually hard, and nobody warns a first-timer: the socialisation window. You have from about 8 weeks to about 16 weeks to introduce this dog to every kind of person, noise, surface and situation it will ever meet. Miss it and you have a 60kg dog that is frightened of things, and a frightened dog that size is the problem everyone is worried about.
The other one is that almost nobody will help you. Most trainers here will not take the breed. Most boarding places will not take it. If it needs surgery you need a vet who can handle a dog that will not simply be manhandled onto a table.
And the thing that makes me angriest: the fighting people. They are why the breed has the reputation, they are why my neighbours cross the road, and they are a tiny minority who have poisoned it for everyone else.