-Scrooge stayed defiant to the ghosts longer, which made me think his eventual change felt more sudden. (Act One ends with Scrooge yelling into the void, "I am a great man," perhaps in both defiance and delusion.)
-It is now possible for Scrooge to interact with the people in his visions
-Belle's character is expanded, the circumstances of her and Scrooge's split are altered (such that as the Christmas Past section ended I felt it was too sudden and left too much out), and she is one of the people Scrooge visits after his reformation
-The Christmas Future section is vastly different. Though Scrooge initially sees Dickens's phantom, the ghost turns out to be his sister Fan. The vision is largely reduced to Scrooge's death (Tiny Tim's death is moved to the end of the Christmas Present section), and his coffin is visited by Bob, Fred, and Belle. I suppose this is meant to carry on the theme from the Christmas Present section that people do wish well of Scrooge despite his miserly nature.