It depends, some Custom Models are much harder and better to do then area changes, and vice versa. It just depends on the time and effort you put into it. You can't bluntly say in general that area changes are harder and better than Custom Models, that isn't right. Everyone got their own level on making things, perhaps I find it easier to do area changes than Custom Models, and you find it easier to make Custom Models more over than doing area changes.
On a side note about the movie, it must be equal and reasonable to each other, you can't have many dbc edits and less area changes for example, it just must be equal so people can see more diversity.
But I'm still wondering how you guys gonna record all of it <.<