It's a quandary best ruminated over with a bottle of scotch and fat cigar (giggling secretary on your lap optional). After six seasons Mad Men, the suavest show on television, is about to amble into the sunset. Can the ‘60s-set drama, so slick, so pretty, succeed where many cult TV properties come unstuck and give fans a sign-off to remember?

Of course, in a way it doesn't matter whether Mad Men finishes with a bang or a whimper. It has already bequeathed a TV character for the ages in the form of womanising, whiskey-glugging advertising creative Don Draper (Jon Hamm), a dapper dude who makes a living spinning fantasies for others, oblivious to the fact that the biggest lies are the ones he tells himself.

In the very first season, Draper's life was a beautifully wrought deception: he had a gorgeous family in the 'burbs and a mistress in the West Village when all he really wanted was to be alone with a tumbler of Johnny Walker and his demons. By the time Mad Men finished its initial 13 episode arc, his world had collapsed inward, his philandering exposed, wife Betty (January Jones) ready to show him the door. Ever since, Draper has lived a feverous ground-hog existence. As season seven premieres, his daughter has caught him cheating on spouse number two while his alcoholism – teetering on full-blown since the start – has seen Draper take a mandatory leave of absence from work.

The tension between men's craving for stability – a wife, kids, a yard – and the urge to run wild and free is a quandary for the ages, serving as grist for the entire canon of writers such as Updike and Cheever (their oeuvre likewise set in ‘60s America East Coast suburbia). In theory, it could make for heavy TV. But Mad Men is just so gosh-darn handsome that the existential murk never drags you under. Indeed, it can be argued that Mad Men is successful not because of its thematic deepness but because of the surface shimmer – rarely has a TV show served eye-candy in such heady quantities.

The charms of period drama are well established. From Downton Abbey to Life On Mars, it's clear audiences would rather fetishise bygone eras than live in the dreary present. At first inspection, admittedly, Mad Men's backdrop might seem comparatively humdrum, white shoe New York being quite a distance from the social changes swirling through America, and the world, at the time.

However, the genius of the series has been the way it holds a mirror to the present by confronting us with a warts and all past. In the corporate ‘60s sexism is rife, racism ubiquitous, puffing a cigarette apparently de rigueur for pregnant women. What Mad Men asks us to consider is whether things have moved on all that much. Sexism and discrimination may no longer be in the open – but, as series creator Matthew Weiner has repeatedly stated, that's not to say they have ceased to exist. If anything, nowadays such issues are perhaps more insidious.

Draper aside, Mad Men is populated with fascinating characters. There's oily, privileged Roger Sterling (John Slattery), born with a silver spoon and a smirk, and slithering Pete Campbell (Vincent Kartheiser), who cheats on his wife in the very first season and doesn't get any more likeable thereafter. The show has also given us some of the strongest female protaganists of any recent series: gal-in-the-city Peggy Olson (Elizabeth Moss), putting splinters in the glass ceiling back when it was made of cast-iron; Joan Holloway (Christina Hendricks), a sad-eyed Jessica Rabbit for whom feminine glamour isn't so much an affect as a shield, to protect her from men and their horrible ways (not that it does her any good).

Though widely adored Mad Men has not been without critics. The major beef is that, for much of its lifespan, it has circled the drain, reprising the same tics and tropes without really moving forward. Certainly, at its most gauche it's as crass and obvious as any soap. The season five suicide of Lane Pryce (Jared Harris, son of Richard), felt like a lurch too far, its pathos unearned while Don's inability to stay on the straight and narrow seems increasingly formulaic: how many times can a man throw his family life under the bus in order to indulge his proclivities? Okay, serial womanisers exist in fact as well as fiction – nonetheless, with Draper one gets the sense we are watching a character cycling through his greatest hits: he will cheat, he will drink, he will stare stoically out his office window. And next week he will do it all over again.

Then, Mad Men's slack plotting may be its salvation. Because the drama is entirely character-driven, few loose ends require wrapping up. Certainly it's difficult to imagine the show concluding in a conflagration of controversy of the sort that attended the recent finale of True Detective season one, where uber fans held out for some sort of metaphysical catharsis the series never intended to provide.

With Mad Men one senses things are simpler. We don't want any reality-shattering reveals or plot hairpins – arguably Weiner dropped his big payoff season one with the bombshell that slick Don was really blue-collar Dick Whitman, raised hardscrabble in a Midwest brothel. Really, all we expect from Mad Men is a stylish send-off, some zesty bon-mots from Roger Sterling, a few sheaves of rumpled wisdom from Don. That our expectations are so low probably speaks to a failure on the part of the show. That we can't wait to watch, attests to how much we love it anyway.

Mad Men season seven airs on Sky Atlantic, Wednesdays 10pm