I finally saw it. It's hard for me to analyze it on a story level because it has the same problem for me as the George Lucas special edition of Star Wars that a lot of the new special effects shots stick out like a sore thumb. Whether they're "bad" or just clearly of another era than the rest of the movie, they are distracting. It begins right up front with the Phantom Zone mirror thing flipping around in space in a bunch of unnecessarily added shots.
I watched this back to back with what I think was the theatrical cut on HBO Max. The movie is almost completely the same and what's weird is scenes that are the same but just have an added or subtracted line of dialogue cut here or there. Of course there are lines I remember that aren't in either version because I grew up with the ABC-TV version that we taped and watched over and over. For example that version ended with the Arctic Police showing up to arrest Luthor and Zod and his cronies at the Fortess that wasn't in either version I just watched. We always made fun of the concept of Arctic Police but really that scene was just there to show that Superman hadn't killed Zod & Co.
The first big change is the Paris scene not being there and replacing it with a recap of Luthor's nuclear missle launch from the first movie. That's fine either way. The Paris scene was okay, I thought.
The honeymoon at Niagra Falls was similar but instead of Lois throwing herself in the river, she shoots Clark with a blank bullet to prove he's Superman. I had heard that was the "proof" in this movie that Clark was Superman. I maintain that it doesn't make sense; Superman should know if he was shot with a real bullet or a blank. It's one of those shock-and-reveal scenes that is cool for a moment until you realize it doesn't make sense. Like the "I'm always angry" Hulk scene in The Avengers movie.
Never mind the fact that Lois had already tried to prove it earlier in the Donner Cut by throwing herself out the window of the Daily Planet. It seemed like too many attempts.
In the Lester Cut, Superman saves Lois from the river without revealing himself as he did in Donner's Planet scene (which was a cool scene BTW). Then he clumsily drops his glasses in a fire and reaches in to grab them to protect his secret ID and Lois sees his hand isn't burned and realizes she was correct. Superman says "I don't know why I did that" and she says "maybe you wanted to" and I think that's a pretty good point. If "Clumsy Clark" is just an act, then he must have done it on purpose, but it was kind of subconscious. That may be true of the blank bullet scene too but they don't talk about it.
Either way I'm not sure why he has to be outed and can't just tell her. It goes back to the whole Silver Age thing where he belongs to the world and has no personal life and can never be with Lois. They explain this in more detail in the Superman/Jor-El scene and some of the reasoning seems a little iffy to me but Reeve's acting is pretty good, as opposed to the "blank scene" which they said was 'screen test footage' where the hair and makeup is quite different and the acting seems a little less polished.
Also the reconstruction team couldn't decide how to depict Jor-El. Sometimes he's a floating head, sometimes a full body. Sometimes the body is giant and sometimes it's normal sized. I suspect they were limited by existing film elements which is another sign that this director's cut was made far too late and/or enough money wasn't committed to it.
The other big change is the ending where Superman turns back time. I know this was Donner's original plan to do it at the end of part 2 instead of part 1, and it's interesting to see scenes that were filmed for that purpose like the staff at the Planet all freezing and turning back. But for the story it doesn't quite feel motivated. In the first movie he defies the laws of time and space to save Lois. This time Lois is not in danger. The crisis is over, and he just spins back time to clean up the mess. But as I understand it, Donner's original idea was that Zod & Co. had done much more damage like destroying the entire U.S. and killing thousands or millions, but that wasn't realized for this cut. All Superman is fixing is that Zod broke the Washington Monument (instead of Mt. Rushmore) and at least he saves the 3 astronauts killed on the moon.
But the order of events gets clunky because first he turns back time and then he goes to the diner to get revenge on Rocky but the first scene at the diner should have never happened. Yet the owner says "I just fixed this place after the last time." I realize that's because this cut is built out of whatever footage they had but at least put it in the right order.
The other curious thing is that the scene of Lois and Clark in bed together comes before he gives up his powers instead of after. Was that a hint that she could possibly get pregnant with a super-baby? This is obviously the thread that Bryan Singer picked up for Superman Returns even though in the Donner Cut, this is undone by the time reversal and in the Lester Cut, she only sleeps with powerless Superman.
All in all a very mixed bag. It's too bad we never got a true Donner Cut in the way that we got the Snyder Cut with proper reshoots and post production. But this one came almost 20 years after the original production.
I guess my feeling is that this is 99% the same movie but far less polished. Music cues, dialogue, editing, so much of it just seems off. That may just be because I am so used to the older version. But it also might be because Donner switched out as many takes as possible to make it different from the Lester Cut rather than just making the best version possible.
Still better then the Lester one, which was corny comedy relief way too much!