I found myself far more in agreement with voyou’s take on the most recent episode, than with the one in Kritik.
Would Joan have made the same choice — to sleep with the Jaguar guy — if Don had reached her in time? Maybe it would have made a difference to know that she hadn’t been betrayed by all her colleagues — that Don, at least, supported her. And surely the use of the flashback is intended to ask the viewer to consider the possibility of regret. But I’m not certain that Joan would have acted differently had she spoken to Don first. At the end of the episode, Don is alarmed and upset to see Joan walk into the partnership meeting, but Joan won’t acknowledge their earlier interaction, and is calm throughout. Ultimately, Joan makes a decision that is terrible and unsavory, but in light of the options with which she is presented and the turn her life has taken, it is also reasonable. I just hate to think of the nasty, smirking comments Pete will make about her when the opportunity arises.
Also — Seriously writers, we could have done without the Megan subplot. We get it.
And I admit it, I cried at the end.
An und für sich 
The Girlfriend predicts that Don will leave the firm in disgust by the end of the season. A consequence that occurs to me: that will render Joan’s shares totally worthless, meaning she would’ve been better off taking the (huge!) lump sum that Lane probably mostly recommended to her primarily for the sake of getting his bonus…
Yeah, I worried about that too, not so much w/r/t Don leaving (which hadn’t occurred to me, although it’s a good point — without Don, the partners will be Roger and Bert, who do nothing; Lane, who is not actually useful in terms of bringing in revenue; and Pete, who seems increasingly unstable), but w/r/t the possible general failure of the firm.
It doesn’t make any financial sense to make Lane or Joan partners. From the firm’s standpoint, you want to turn workers who are potential long-term revenue-generators into partners, in order to give them an incentive to bring in money. So, making accounts and creative people into partners is sensible — you want to tie their fortunes to the fortunes of the firm. You generally wouldn’t want to have the accountant and office manager be partners, except of course, that these oddities have been explained by the show’s plot. But having only two partners out of six who are in any position to generate business seems like an untenable situation.
And we’ve already established that Don isn’t good at actually bringing in business from scratch (with Hilton). Man, can he close, though.
Also, I agree with voyou that Don’s attempt to intervene in the Joan situation was out of character. Equally jarring was Roger’s almost total lack of interest. Roger genuinely loves Joan, at least kinda sorta, and anyway why would he care that much about Jaguar, especially since it’s probably going to be Pete’s account?
Roger’s only protest is a sniffy comment about how it’s a dirty business, which also didn’t make a lot of sense. Roger is a kid, with a kid’s narcissistic, highly personalized view of the world — he would care about the Joan problem because it has to do with his Joanie, not because he has any interest whatsoever in abstract business ethics.
Okay, just catching up now.
Don’s attempt to intervene in the Joan situation was out of character if you think that Don believes that people should make the most of their opportunities and not get too sentimental about sex (the way Roger almost definitely would — astutely observed).
But I think Don’s image of himself is pretty close to the image that the Kritik article has of him — that he’s powerful enough to walk through the world as a “creative” type who’s above money grubbing. He admires Joan, and thinks of her as a lesser model to him — someone whose force of personality is enough to get what she wants to come to her frictionlessly, who doesn’t need to bring what she has to the market.
The Megan storyline is on the nose w/r/t the Jaguar ad, but it sets up the emotional punch of Peggy’s departure. Having recapitulated Megan’s unpredictability into a creative victory, Don’s women–individual and independent, but only just so–are under his thumb. And then they’re not.
I cried at the end, too.
John Slattery, who plays Roger, on Roger’s failure to intervene:
Well, I mean, I was a little surprised that people were so shocked she would undertake that transaction. She’s done other things — she’s slept with other people before, she’s a sexually confident person, she knows what she’s doing, and this was an opportunity for her to set herself up for the rest of her life. She’s probably undertaken transactions like that for less. I don’t think it was necessarily Roger’s place; if she’s negotiated terms to her satisfaction, then good for her.