All the goofy stuff is cut out...more cool scenes, the Zod Crew destroy more stuff, more white house shenanigans,..no hypnotic kiss, no stupid celophane "S" being thrown, no guy talking on a phone while being blown down the street, no Paris, etc...
The way in which lois finds out about clark is also better...
The way the phantom zone cracks is also better and is in context to the first film...
He goes back in time again at the end...
All in all even with the well done test footage being used at the Niagra Falls scene this version is muuuuch better and makes more sense. Bravo to Donner's assistant guy...
It also makes Superman Returns make more sense--because "the son becomes the father the father becomes the son" kryptonian prophecy is played up in the donner cut and makes Returns more fluid to follow... i now like Superman Returns better because of this version of II.
