Scabior was rarely mentioned in the book, as far as I can remember. I wonder why they replaced almost all of Fenrir's parts with him. I was kinda looking forward to it because it seemed a lot better. I didn't even know what Scabior looked like until the movie brought him up. I think he brought up the fact that many people that the Snatchers caught thought that they would be let go if they told them that they were in Slytherin House and challenged them to tell them the location of the dormitories, and I think that was the last of him.
As far as the movie goes, they most definitely better, they put him on this far and made him hot enough to be missed by many fangirls including yours truly. xD