Ok, your reply is two weeks old, so it may be obsolete to respond to it, but I wanted to mention that it indirectly inspired me to arrange a minor Kurosawa marathon by borrowing a box set from the library (turns out I’m less educated on the man than I should be, and, if anything, I have no current university course and thus 100% spare time for another two weeks).
My general verdict after this viewing would be that Seven Samurai is indeed an extraordinary film, but somewhat the contrary to you, I would call it the overlong film compared to GBU and OUATITW, albeit just slightly. I think three hours (that is, maybe 20-25 minutes of trimming, mostly in the first half of the second act) would have been perfect, but maybe I could have embraced the 200 minutes entirely if some focus had been shifted towards the robbers, like maybe at least giving its leader a name and some characterization (…and there you have the one improvement The Magnificent Seven made upon the narrative). And that said, I definitely still think Kurosawa has a striking ability to make time flush away - Ran, at 160 minutes and inferior to Seven Samurai in most departments, is still never boring (although a bit messy at the start), and even the disappointing Throne of Blood passes the time.
It should be said however that some of the circumstances of my viewing worked against it, such as the five minute intermission, which just puts your attention off a bit when you watch the film from your sofa - why didn’t they drop it from the home video release? - and an incident which happened about 40 minutes into the film when my father overheard something which he thought sounded like “Vad fan har du gjort av bollen?!” (“Where the hell did you put the [foot]ball?!”) and nearly ruined the whole experience. I had to pause it and come back some hours later before I could take it seriously again (Lesson learned: If you’re to watch a Japanese film, especially one with much shouting and aggressive talk, make sure everyone in the room can see the subtitles and know the context - it’s a hopeless language). But to me, Ikiru is Kurosawa’s definitive masterpiece, with Yojimbo close behind - although the next film on my AK watchilist, Stray Dog, looks very, very promising to me despite not being among hist most acclaimed works.
But most prominently, I’m very curious to know exactly which sequence from, for instance, GBU you would find expendable. The dialogue-free introduction of Tuco and Angel Eyes? Would fail to set the mood for the rest of the film. Tuco’s visit at the gunshop? Would discard one of the comedic highlights. The sadistic march through the desert and the subsequent meeting with Carson? Could perhaps be cut by a minute or two, but that wouldn’t make any overall difference. The sequence in the Union camp? Would leave the alignments for the rest of the film incomprehensible and take away a great part of the anti-war message. The bridge sequence? Same there, and we would see less character development between Blondie and Tuco. You got the point long ago by now, I suppose. To me, GBU is a long tall tale where every scene is a piece of a puzzle. Could OUATITW be cut down? Yes, but cutting more than like ten minutes at most - mostly in the first half – -would ruin the melancholic, epic, almost solemn feel. Just look what the 145-minute American cut did to it (and as usual with studio-imposed cuts, they managed not to cut those minutes that were actually expendable).
In conclusion, here’s a disclaimer: Kurosawa is still a relatively new acquaintance of mine, while Leone had been a hero since my childhood. In just a couple of years, I could very well find myself appreciating the former’s work even more.