Shaw's is the face behind the mask of Vader. Except for David Prowse, who is actually the face behind the mask, but you know what I mean. Seeing that face restored, happy, approving of his son, in communion with his mentor ... there's a lot of strong feelings there. He has been in a dark place for twenty years, but he's found his way home, and his friends were waiting for him.

Hayden's is the face of pride, resentment, and foolishness. The prequel trilogy spent four hours linking these attributes with that face, prepping us to dislike him. When I look into that face in Jedi, I don't know what he's thinking or feeling. He has no camaraderie with the geriatrics he's hanging out with, that's for sure; he's more like a bad child who avoided a scolding by flashing his puppy-dog eyes at his parents.

To answer your question, I think Ronnie summed it up pretty well: "There he goes again."