Yes, that being said, the quality is only as good as the source. But for the most part, the sources are very good. There are of course lots of different sources, both official and unofficial, some of which I'm sure you can guess. There are some cases of over modulation and things like that but again, in these cases the sound is only as good as the source. That doesn't mean the quality won't be the highest possible.

I should also perhaps point out that as well as remixing and re-engineering the sound, a lot of the sources have different speeds, some slight, some dramatic. This is mostly because a lot of the music that has leaked over the years was sourced from tracks after they were speed changed (not always the same speed) for the film.