But we don't need to see Supes flying back in time to save the world again, do we?
No. But had Donner been allowed to fully see his vision, the first film wouldn't have ended that way. It's only too bad he didn't have all the necessary footage to do a similar project for the first film so he could show how he intended to work the cliffhanger.
The Lester version, definitely.
I've only seen the Donner version once but something felt...off. I didn't really like the editing of it much.
To be fair, the Donner version isn't so much a film as it is a glorified storyboard. So judging it on the merits of editing isn't really fair. He essentially had to paste together a sculpture using bits and pieces of already formed clay that were either incomplete or not even his.
Donner's film is so much more focused--even with the editing shortfalls. The themes and concepts are tighter and more defined and the story is a lot more coherent.