Yes, the end of Donner cut is a mess. This is because Donner never filmed an ending, and refused to use Richard Lester's.
As it stands, I think the Donner cut is vastly superior, but I think Donner should've used the Lester ending. I always miss the scene at the white house.
I prefer using neither ending. Just use the Donner cut, but end the movie when Superman leaves Lois on her balcony and flies off. (Or if you prefer, cut directly from there to Superman visiting the White House and then flying off into space.)
There's no reason for them to do a reset that has Lois forgetting Superman's identity. Any such reset is a dramatic cheat IMHO. Yes, leaving her memory intact screws up the continuity on the following movies, but the following movies are stupid anyway.