But would the response to those episodes change the approach to series three, which premiered on ITV tonight? It certainly seems to be the case. The show's hit a new decade, moving into 1920. But while we're faced throughout the episode with the way the world is changing, in fact Downton Abbey seems to have restrained itself.
It might have begun with a 90-minute episode, but everything was much more low-key. The decision to begin the series with a wedding was indeed a bold one, considering that so often nuptials are used for the final moments of a show. But with so much time devoted to the planning of the ceremony - and the drama about whether Mary and Matthew would actually go through with it - other characters and storylines were largely relegated to the background.
That meant that the episode felt mainly like it was setting up ideas for the rest of the series - O'Brien and Thomas turning against each other because of new footman Alfred, for example, is a genuinely interesting direction for the show to take, but we got to spend almost no time with the scheming duo besides a couple of snarky lines.
It's likely that Alfred will become an interesting character in his own right, but for the moment we had to make do with the basics - that he was trained in a hotel (the horror) and that he's too tall to be a footman (to be fair, it was very cute to see his livery not quite fitting him, with the jacket sleeves hovering above his wrists). It could well be that the resentment he causes will be great fun to watch, as Carson gets frustrated and Thomas turns on O'Brien, but we'll have to wait and see.
Indeed, that was the theme with much of the episode. Again, the relationship between Edith and Sir Anthony is potentially intriguing (does she really like him, or is she just desperate to catch up with her sisters?), but I was left searching for a little more to hang on to.
At least we got a kiss on the cheek between the pair, whereas Bates and Anna fans had to be temporarily pacified with some cute lines ("I'd rather work to get you free than dine with the King at Buckingham Palace") and not much action. We were introduced to a possibly troublesome cellmate and Anna is clearly on a mission to free her beau so there's the promise of drama to come, although to be fair I don't know if I'll be satisfied until we get a Detective Anna spinoff, where she solves crimes in a trench coat with the help of just a newspaper with eyeholes.
That's not to say there wasn't plenty of big stuff going on, too, besides the wedding. The closest the episode came to Downton's classic melodrama was an entertaining appearance from Sybil's former suitor Larry Gray, an over-the-top posho who is so evil that he walks around with a permanently raised eyebrow and a smirk that would sour milk.
Yes, he's such a cad that he spikes Branson's drink to make him seem drunk at dinner. Of course this would never happen, but if you're a fan of Downton's silly soapiness than this would be a highlight of the episode - the outrage, the Violet asides and Larry's disappearance (much like is-he-or-isn't-he-Patrick from last series).
It's a shame that the Irish troubles are laid on thick - like applying icing with a spade - but it is quite interesting to see Thomas adjust to life upstairs instead of downstairs. As is often the case, Downton Abbey deals with this best in the little moments - forget about the endless dull outbursts and dinner and focus instead on adorably awkward Branson making a visit to the downstairs staff to prove he's not changed too much.
It was a little disappointing, though, that Tom ended up in the much-detested morning coat, and I was left a little confused about exactly what message Downton was trying to convey. Still, I'm maybe being unfair - it seems that the Earl is having to make sacrifices, too, as he stops himself from being "indignant" when Branson dares to express an opinion about Mary and Matthew.
Elsewhere, Shirley MacLaine's much-trumpeted arrival as Cora's mother Martha was entertaining enough, though I was surprised that Violet still grabbed the majority of the choicest lines (my favourite came early in the episode as she vowed that Branson would behave because she would "hold his hand on the radiator until he does"). The pair did have some entertaining dialogue ("Oh dear, I'm afraid the war has made old women of us both", "I wouldn't say that, but then I always keep out of the sun").
But while they represent the differences between old, traditional Britain and new world America, I'm a little concerned that their relationship has already been smoothed over now that Martha knows Violet gave Sybil and Branson some money to travel to the wedding. Hopefully, we can expect more fireworks in the future.
In fact, many things seemed to be helpfully resolved before the episode was out, whether it was Daisy going on strike and then off it again, Branson eventually becoming Matthew's best man, or (mostly) Mary and Matthew's relationship itself (I have to mention that lovely scene where they talked out their problems with the door in between them and then kissed with closed eyes, because it could melt even a heart made of stone reinforced with steel).
The only thing still left a little uncertain (besides Molesley's future, which was another example of Downton doing the little things well) was the future of Downton Abbey itself. The financial problems faced by the estate are probably (hopefully) setting up a series-long arc which will force the upstairs residents to approach the world in a different way; it's no secret that it became very tough for the aristocracy, money-wise.
It should be interesting to see how the Earl copes - whether he is the "failure", the one who "drops the torch and lets the flame go out" - and how Matthew reconciles his guilt about Lavinia's death with his responsibilities as a new husband to Mary.
But for the moment, we can all just enjoy a good wedding, because who doesn't like a good wedding? Downton always does stuff like this well, and this is no exception. Whether it's the village excitedly waving flags or the touching moment as Mary asks: "Will I do, Carson?", this is one of those television weddings that would have you reaching for a handkerchief to delicately dab your eyes.
The question that remains is just what kind of show Downton Abbey is and what we watch it for, whether it's soapy melodrama or carefully-observed period drama; whether it's evil lip-curler Larry Gray or quietly heartbroken Molesley. Possibly Downton can be both at once, and do it successfully, but that will only be revealed as the series unfolds. I suppose if the show could speak, it might just echo Lady Mary's fantastic closing line: "I should hate to be predictable."
Downton Abbey airs on Sundays on ITV1.