I have a pyre mix now and had a Husky mix. Both are hard-headed, difficult to train and independent thinkers. Both are/were awesome in the house with my Husky being the first dog I met that could sense every emotion and adapt.
My Pyrenees mix has two issues you should consider that are endemic to the breed:
Barking at the fence
Extreme need to protect her pack
I am not saying she is an attack dog by any means but she will get between me and any potential threat and hold her ground. Any dog that approaches the other dogs in the pack must pass Roxie before greeting any other dog.
Also, no off-leash activity until the dog has established its territory and then only off leash in that territory. They will range and establish the largest possible area as their territory given a chance. My husky would just go for a run and come back (if she escaped) when she was tired...Roxy with spend hours patrolling.