Flippers: Pre-hung or slab?

[Drew Clements]

I've got a couple flips where I'm planning on replacing all of the interior doors with pre-hung units since the existing jambs are pretty beat up (some kicked in)... but made me think to ask this question:

If the jambs are in good shape, but the doors need to be replaced (say it's a style issue only) AND you'll be replacing the trim, do you go for pre-hung or slab in that case?

What do you do and why?