Season 4 opening (spoilers): It was a slow start for the most part. The new setting took me awhile to adjust and at first things seemed to be just the same. I loved Peggy going between a strong, proved creative lady and her old image as Don's young, unprofessional protege. Don, like me, couldn't adjust to the new position and era, but eventually something snapped in him and the end was fantastic. I don't really get why he needs to pay a woman to sleep with him all of a sudden... and what was that kinky part all about?
Roger was great as always. Joan was bitchy like she and everyone else love, but I still think her presence was pretty weak. And what about Lane Pryce? He's now a partner, but he was barely there. Betty and Henry's marriage life was boring (yeah, sure, the writers aimed for that...) and like his mom said, it's only based on passion. Sally will one day slap her mom and I'll cheer for her. I'm glad the young actress gets a recognition with a main credit. Pete was... okay. So far, I like the new kid (Matthew Long from Jack and Bobby and Ghost Rider). Surely there'll be something between him and Peggy.
Loved the second meeting with the bathing suits people, the two interviews, Don kicking a chair, having a date with a girl that looks just like Betty (Anna Camp from True Blood), Sally during Thanksgiving dinner and the ham part (they work too much with SNL...)
Didn't like the prostitute/slapping part, Betty's childish and obvious attitude, the slow pace (even for this show, it felt too slow), no references to 1964* pop culture.
* The episode was set about a year after JFK's assassination (see Season 3), the week of Thanksgiving that year and after the murder of civil rights activists in Mississippi the same year (referenced by Don's date).