Can you give me some info on Bernese mountain dogs!?

I am researching this breed and i want to know everything about them. Can someone who breeds bernese mountain dogs, tell me all about them? what is their temperament like? what is their lifespan? are they a domineering breed? are they stubborn? are they hard to train? how much do you need to groom them? do they make good guard or watch dogs? how bad is their health? are they loyal and affectionate? are they easy to train? can you tell me everything single thing about this breed? Can someone who breeds bernese mountain dogs please answer??? or anyone else who knows plenty about the breed, please answer?? Thanks lots:-)