The version they showed was a 1984 restoration by Giorgio Moroder. Although he was able to add back in previously lost plot point using some still photos that had been uncovered, he also replaced the intertitles with subtitles, added various color overlays throughout the film and re-scored it using pop music ranging from Adam Ant to Freddie Mercury to Pat Benatar. Here's a sample...
The image quality was so bad that, in some scenes, it was really difficult to tell what was going on, even on a big screen. Not to mention that the movie is shown slightly faster than it was originally filmed, sometimes giving the characters awkward and jerky movements. Plus the score really just did not fit AT ALL with the imagery you could see.
But I was still able to see beyond all that. I could discern what Lang had done, at least in part, and I could tell that he had still created an incredible piece of storytelling. That was definitively proved to me last night when I saw the recent "complete" version that was just released.
I also had a similar impression when I saw the movie Tank Girl. I generally don't like "comic book movies" but I do periodically get into extended moods where I do try to watch some of them just so I have a point of reference when a non-comics person says, "You like comics? Cool! I thought the Iron Man movie was really awesome!" So I sat through Tank Girl about five or six years ago. I won't irritate you with a clip from that, but suffice it to say that it wasn't very good.
But I could still see remnants of Jamie Hewlett's and Alan Martin's original creation throughout the movie. (In some cases, literally, since some of Hewlett's art makes it onto the screen.) Sure enough, when I picked up some Tank Girl books, I was not disappointed.
It's much more difficult to go the other way, though, it seems. I saw the Howard the Duck movie well after I was acquainted with the comic, and couldn't find anything redeeming in the film. I had trouble liking the Fantastic Four movies or the Flash television show or the Batman films or...
It's easy to say "it loses something in the translation" but I think there's more to it. I think I respond to a slightly different set of elements than most people. So when I see a movie like Ghost World, I'm responding to aspects of the original themes and ideas, not whatever may have been inserted for larger movie-going audiences. So when I return to the original, I find at least those same elements and, often, a few others that had been stripped out for the movie.
It's not just comics to movies, of course. I often run into the same issue going from movies to comics. Or novels to films. Or whatever. It's rare that I respond more strongly to the adaptation than the original. (In fact, the only real exceptions I can think of are the works of Jules Verne.)
I suspect that has something to do with a "too many cooks" factor. That the second creator is adding/reinforcing his/her own ideas, which don't necessarily mesh with what I get from the original. If I'm not yet aware of what exactly the first creator is saying, I can parse out some of it from the derivative work, which then leads me back to the original. It's that "too many cooks" idea that's why I generally don't like movies and TV in the first place. Get me as close to a single source of good ideas as possible, and don't cloud (what I interpret as) their message with additional noise.
But that's probably just me. Here, have some more of Moroder's Metropolis...