my best friend had one, and it got shot last winter by some guy down the street. it busted through the electric fence, and ran down 5 yards, some guy thought it was a polar bear and shot it with a 22. in the ass, didnt even make the dog blink, but it came home anyway.
cool story.
but yeah, super hard dog to train, and is nearly impossible to keep them confined in a fenced yard because they will find a way out (really smart dogs). but good luck if you do get one. they are super cute when they are puppies. and be prepared to deal with alot of drool, ALOT of it