That was interesting. Good find. I can appreciate the time and effort that went into making that vid.
I'm not sure I entirely agree with his conclusions, though. I admit it may very well be because it was the version I saw first, but I remember walking out of the Fincher version and thinking that, while good, it was not as good as the Swedish version.
While it's been so long now since I've seen either version that I can't remember much in the way of specifics, watching that video I am thinking that this is less a discussion of which version is better (as he asserts) but rather a matter of preference. The Swedish version, I think, is more naturalistic and grounded; the Fincher version, by comparison, is more Hollywood, more stylized, more melodramatic.
At the end of the day, both films are very good. If anything, the real story here is Niels Oplev crafting a film that is arguably equal to Fincher's (if not better, as many would say) with only 1/7 of the money. That's amazing!
It's a shame that Fincher did not follow up with a sequel though, because I never saw any of the Swedish sequels and therefore it would've been an entirely fresh experience with no expectations based on previous movies.