I'm only up to the beginning of season 5 personally, but he's a very unlikable character to the point where I imagine I'd be thoroughly indifferent to any misery that besets him.
He's not the only one though, there isn't a single person in Mad Men that I like, probably one of the reasons why despite it's quality, I can't get into it. I feel like slapping each and every single one of them.
Contrast that to Boyd from Justified, he's scum but you still end up liking him, or any of those guys from the Shield.
Speaking of Justified, I think the 3rd and 4th seasons are great. The pace to season 4 was fantastic, they managed to pack so much into just 13 episodes and yet it never felt rushed either. Great to see a show that's actually progressing as it goes on. Hopefully they can find another level to it next year.