https://tygerbug.tumblr.com/post/795839761406427136/i-was-trying-to-explain-superman-2s-editing
At this point, since it was last seen on television in 1987 or so, people aren't familiar with the extended TV cut of Superman II (1980, Richard Lester and an uncredited Richard Donner). People assume that the 2006 cut by Michael Thau released as the "Donner Cut" is the same thing, when there is very little overlap between the two (and the Thau cut is amateurish and strange). To date, the extended TV cut (once released on fan DVD as the Restored International Cut) is the only version which was not made as a middle finger to one of its two directors. It presents many previously-unseen Richard Donner scenes in full, scenes directed during the making of Superman (1978). Gene Hackman in particular is very well served by this edit (in the Lester Cut, he is often played by a voice impersonator and a double from behind). Margot Kidder's tearful goodbye to Superman toward the end is also an all-timer. Thau used very little of this. (In fact, the "deleted scenes" reel in SD is the only time we see any of these scenes in their original form.)
WB could right this wrong by releasing the Extended TV Cut on Blu-Ray, as it did for Superman (1978). In the meantime, I've been looking into doing some editing of the material myself, to allow for different special effects and more RIC/TV cut material. I just edited a ten-minute reel and have been in talks with thebooshman who did several fanedits of this film previously.