I'm glad they aren't seeking sympathy for Don's character as much as they might have in the first two seasons. Sure, he cheated and drank and lied, but the harder edges of the time, namely the racism, sexism and heterosexism never seemed to sway Don as much as Roger or Betty. I'll always sympathize with the non-bigot in the room, if surrounded by bigots. But now Don's acting out the times, with his constant cruelty toward Peggy and in this past episode, his treatment of Salvatore, specifically using the phrase "you people."
I really thought they went too easy on him for a while, but now they seem to be showing the rougher edges.
This whole post, of course, hinging on not considering Don's actions in season one anti-Semitic, which while they certainly were, I think the show was trying to justify them, or at least explain them.