I see judging by the near-universal praise for this story I'm going to have to fight my case for my rather different opinion of it.
From now until the end of the Pertwee era, longer stories are the norm. A six-parter is not merely a longer four-parter, it's a whole different beast of a story, and although budget problems can sometimes preclude broadening the scope of a story to fit the longer length, this isn't always the case and in The Abominable Snowmen, a six-parter, an otherwise polished, expensive-looking production (by 1960s Doctor Who standards), I lay the blame at the feet of the writers for pulling out all the stops to slow the story down - you know what I mean: slow-talking, slow-moving villains, going back and forth between locations for little reason, extended scenes with little dialogue or action, characters not realising the bleeding obvious, all hallmarks of padding out a story beyond its natural length.
The BBC audio of this story was dreadfully quiet. I tried to listen to it when I was out and about but could hardly hear a thing, necessitating a relisten of Episodes 3 and 4. Let me bactrack a bit and start at Episode 1 though.
The Doctor decides to return an old relic to the monastery at Det-Sen when the TARDIS lands in Tibet in the 1930s. There's lots to love about the first episode - the Doctor's massive coat (looks warm!), the location filming (always fun to get out of the studio, even if it's just some hills), the pure atmosphere of the episode - very calm before the storm as the plot slowly gets going. Unfortunately upon arriving at the monastery the Doctor is suspected to be behind the murders of some monks and a comrade of Professor Travers, who has come to Tibet to look for the Yeti. I've never been much of a fan of these misunderstanding subplots, since it's inevitably going to be resolved it requires decent characters to be hostile and for little reason other than the story is not yet ready to advance. The lead monk, Khrisong, is a fairly humourless character and so remains pretty unlikeable throughout the rest of the story. Troughton's Doctor is of course entertaining but by the end of the first episode even he is struggling to stop viewer interest from waning.
The Doctor's decision to leave Jamie and Victoria in the TARDIS gives those two characters a chance to interact more. One thing I like about this story is the way it builds on Jamie's protectiveness of Victoria, like she's his little sister. As they leave the TARDIS and follow some footprints, they get trapped in a cave with a Yeti, which provides us with the story's first cliffhanger.
The second episode survives, yay because it's a good one. The picture on the location filming is very sharp and grain-free, so much so that the black and white looks more like a creative choice than necessity, although it does make it all the more jarring when we cut back to the studio, especially considering the Doctor is supposed to be outside too. The story is still slow-moving but we get a good scene with the Doctor speaking to the young monk Thonmi in his cell. Thonmi is the most likeable of the monks, showing more willingness to listen to the Doctor and quickly trusting him. If Jamie wasn't around he would have made a good addition to the TARDIS crew.
After taking an age to reveal his possession of the Ghanta, the Doctor is tied up outside to draw out his "allies" the Yeti, while we get our first glimpse of the sanctum of the monastery, where we meet the Abbot Songsten, an elusive, guarded but forceful man, and hear the voice of Padmasambhava. Both are clearly up to no good. Jamie and Victoria convince Travers that the Doctor isn't the attacker and he is freed by order of Padmasambhava, giving the story permission to actualy begin with investigaton of the real culprits, the Yeti.
The real stumbling block with The Abominable Snowmen comes in the middle of the story, where two whole episodes go by with nothing happening. The monks capture a Yeti and some control spheres but lose them. We are told at the Yeti are actually robots, inert without their control sphere, and that Padmasambhava is controlling the movements of the Yeti from his chamber, moving them like chess pieces for purposes as yet unknown. This simply isn't enough plot to sustain two whole episodes - even the foreboding atmosphere I noticed earlier in the story has fallen by the wayside. On the whole I think the Yeti are a great idea done badly; iconic look and central idea, but they don't actually get to do anything interesting, just move around a bit. Where are the masses of attacking Yeti, destroying everything in sight? There seems to be no attempt to establish them as a formidable force, or even give them a lot of screentime. I know they are only being controlled, with the Great Intelligence pulling the strings, but people don't generally remember the Great Intelligence when thinking of these stories, they think of the Yeti.
The story occasionally drops hints about the Doctor's previous visit to Det-Sen 300 years ago. I liked the notion of the Doctor returning to somewhere he's already been, and meeting one of the characters, although not enough is made of it - strange in itself as there was plenty of time to elaborate on it. It only raises more questions than it answers. A missed opportunity.
Victoria gets a lot to do here, establishing herself as an independent character who is willing to do her own investigating. After finding Padmasambhava's sanctum, Victoria is put in a trance and returned to the Doctor to convince him to take her back to the TARDIS, a ploy to aid the Great Intelligence whose movements of the Yeti are designed to scare the monks into leaving. We see Victoria at her best and her worst here; there is lots of screaming and she is especially irritating when asking the Doctor to take her away, but she pushes the story forwards and accomplishes more than Jamie does, with Jamie being largely a spare part who worries only about Victoria being missing. Unfortunately, writers Mervyn Haisman and Henry Lincoln don't have a strong grasp of the characters of Jamie or the Second Doctor, and there were moments I was expecting the usual Doctor/Jamie banter but ended up disappointed as it just wasn't there, even though the actors were doing their best. In fact I can see this story being better if Jamie wasn't in the story at all and the Doctor arrived with Victoria. I'm still not keen on the overall triad of the Doctor, Jamie and Victoria, but we see so little of it in this story beyond the first and last episodes there's not much to comment on there.
As we head for the conclusion, Episodes 5 and 6 are a vast improvement on the middle episodes. After sitting around working things out for two episodes, the Doctor becomes more proactive and goes to see his old friend Padmasambhava, who has been kept alive by the Great Intelligence and used as a vessel. The Intelligence starts manifesting itself physically through a pyramid of spheres, having failed to clear the monastery of the monks. The Doctor cuts off the link between the Intelligence and the Yeti, leaving the Intelligence powerless. The climax is exciting enough, with the rampant Yetis.
The Abominable Snowmen is a story there isn't anything more to say about than for a four-parter because a four-parter is what it should be. It's great that the production team got more use out of the location and a monster that quickly resonated with the public, but none of that stops the story from being one of the dullest yet. It has plenty of potential, but it's hardly used; Travers is supposed to be a central character and I wanted to see more of him. The Doctor's previous visit to Det-Sen should have been played up more rather than just being an anecdote. The Yeti don't have enough to do and aren't scary. If they'd just been able to sustain the atmosphere of the first few episodes it could have been so much better. This doesn't mean I've taken the good for granted though, and there's lots to like - the plot and budget hold up and the Great Intelligence is an interesting villain who just happens to irk me by talking so slowly. Perhaps I need to work on my attention span a bit....
Horror quotient - I suspect childhood memories of the Yeti are down to The Web of Fear, I'd be surprised if anybody remembered a walk around the hills more than a dark, tense, underground horror story.
Comedy quotient - Patrick Troughton does his best of course, as does Frazer Hines, but they're working against a fairly serious script. The Doctor and Jamie are thus quite subdued from what we're used to.
Drama quotient - The story was going for dramatic but ended up boring. It's a difficult line to tread - it isn't the first story to fall victim to this and it certainly won't be the last.
One of the dullest Troughtons. If you want Yeti listen to The Web of Fear instead.