In the last two seasons they've really pushed for Pete's physical appearance to mirror his fairly rotten personality, sort of like the Picture of Dorian Grey without the picture. While I can appreciate the symbolism (and symbolism's what Mad Men's all about) it does make me sad, he was beautiful and now I don't know what he is. Vincent has really committed himself to the role, purposely gaining weight and having his hair shaved back to fake a receding hairline. And that's what I really wanted to mention, the hair. I should find picture(s) to post about it but I'm still intimidated by this site's copyright warnings. Luckily I found a site that with a slideshow on this to save me the trouble.
So the hair. Looking at it in Season 6 it has consistently looked fake and distracting to me. I've tried to figure out what annoys me the most and I think the problem is the hair's receding without getting thinner on top. There should be decrease in volume and length relative to the hairline receding, they've done only half the job.
Anyway I might be clutching at straws but there were tiny moments towards the end of Season 6 hinting that Pete might become a better person in Season 7 so if we're lucky his physical appearance might also improve (maybe his weight?).