I obviously have the upmost confidence in any gun I put on the nightstand and have both autos and revolvers that see nightstand duty so it's not a matter of trust that they'll work. For your fantasy scenario I'm gonna say revolver simply because I don't have a auto capable of launching a 275 gr Barnes DPX Solid copper HP at 1500 fps.
Now I got a question for you.
Since you have this crystal ball that tells you exactly how your gunfight is going down, why not just ask for the room at the other end of the hall or maybe drive another hour to a hotel that isn't getting robbed tonight?