The intentional breeding of this mix is just a bad idea. It's not a dog for an inexperienced owner. I'm sure it's adorable as a puppy and you think maybe you're just getting a larger, sturdier golden retriever. Nope. Other than shedding, he shares virtually no qualities of a standard breed golden (we had one of those for 10 years).
Our boy was chipped, so obviously someone thought he was a keeper. But he'd been in a shelter and two foster homes before he turned 3. We're guessing it's because of the ceaseless barking, which is the most infamous trait of the great pyrenees, which is bred to patrol livestock and be an independent thinker, so when he's outside, he "takes suggestions under consideration" instead of following commands. He's still pretty bad on barking, but much better than when we got him. He terrified our next-door neighbors for the better part of two years, so we appreciate their patience.
Didn't know how to play, at all, when he moved in. Will not play with a ball or frisbee to this day. Doesn't know how to play with other dogs. Did learn how to play tug, but only with a stuffed chicken toy (he now has three) as he ignores all other toys. He'd snarl at other dogs and sometimes people when we walked. Was nearly impossible to groom as he'd snap constantly. We actually went to a dog psychologist at one point and attended classes to deal with fear. The only thing he reliably enjoyed doing was getting in the car, any car. When we visited his foster family for an evaluation, he jumped in our car when we were getting a leash, and wouldn't leave. So we just left with him, lol.
Now he ignores other dogs and people when we're on walks and I can safely let him off-leash on trails. Much better at following commands. He trusts us completely. And if there's a dog equivalent of finishing each other sentences, we're pretty much there. Wouldn't trade him for anything.