I love Donner's original Superman film, and I understand that eh shot scenes for the second to make them one big film apparently. That said I hate the Donner cut of Superman 2. The scenes Lester added added a bit of levity to the proceedings. And I listened to Donner's own commentary, and, man what an ass.
The scene where Superman save Lois falling out of a building was unbelievable to me. Sure, superman can go that fast, but I'd always imagine that he wouldn't be able to move quite that fast (like the speed of electricity) without building up to that speed for a least a few seconds.