Banishment vs Dust to Dust -- which do you prefer?

[tinkthank]

Which spell do you find better against larger quantities of yucky undead: Banishment or Dust to Dust?

Let's say you have a unit which can cast both (MotD, Caelum Hero, etc.), and you are facing lots of lower-quality undead (not equipped SCs).

Banishment: Larger area, no fatigue, but smaller damage, can be MR-negated.
Dust to Dust: Small area, 20 fatigue, more damage, cannot be negated.

Which do you like, and why?