I think Thor is going to be one of those 99% potty trained males for the rest of his life. He won't mark in my home, office, stores, or any other normal area. However, if he smells another dog's pee, like at PetCo, or at his doggy daycare, he will make sure he gets a word in, so to speak.
He was neutered early but he looooooves to mark outside. He is also pad trained, so he knows it's okay to pee indoors sometimes, if it's in the right place.
We moved offices recently (he comes to work with me), AND his former owner came back to help with that, and he went to pieces. He pooped indoors a few times, and also peed. He knows where his pad is at work and uses it -- every time his first owner comes back, he starts peeing everywhere. Maybe because she never got him fully trained.