Ben,
I ultimately just stuck with the Superman movies that I LIKE.
All together, I bought Superman the Movie, Superman II (theatrical cut), Superman II: The Donner Cut, and The Superman Serials.
I just can't justify getting a set where I know I don't like half the movies or could care less about some of the features. As much as I like some extras on the DVDs, I have little use for most of the blathering by directors and stuff like director's diaries that requires more time than I have in this life!
I saw an edited version of the Superman documentary on A & E (Arts & Entertainment cable channel in the United States) and it's one of the few documentaries I've seen recently that I had little use for... and this is coming from a guy who IS a major superhero fan! That's how bored I was by the thing. And I watch documentaries on cable all the time!
I knew I WANTED the best copies of the Fleischer shorts I could get my hands on and it was happy circumstance that WB decided to stick the shorts as extras on the Superman I and II (theatrical cut) sets. The Donner cut was a no-brainer since this is one Hollywood myth that proved to be true and I can't stop from looking at a potential trainwreck more than anybody else!
(Honestly, folks, most people that have seen the Donner Cut seem to like it better than the theatrical version of Superman II. Of course, the special effects still stink, but they've been bad since 1978 in the series! Even Superman Returns has more than its fair share of special effects gone wrong including a robotic director!
(What made the first two Superman movies special was NOT the effects work but the chemistry between cast members and the humanity Christopher Reeve brought to a character that most people felt was glacial. That's the real legacy of these films...)