At close range? Unarmed. I’m not trained to use a firearm and so in that particular situation, having one would only get in the way. I just want my hands and my wits. I would be looking for an opportunity to grapple. The gun might be useful as a melee weapon, but in a close-range situation, I’m really just hoping I don’t get shot. The chances of me getting shot go up if the guy who managed to get the drop on me thinks I might shoot them if he leaves me alive.
At longer range, then I’d want a credible threat to present to my attacker after I ducked out of the way and hopefully behind concealment / cover. That would be preferable in my mind to just keeping running. I think I’d end up firing a few suppression shots, then just taking off. I think that would provide just enough discouragement to prevent a pursuit.
This assumes I actually know how to use the thing well enough to be able to fire it. The last thing I want to mess with is safeties and loading the chamber when there’s an active threat against me. If it doesn’t go bang when I pull the trigger, then I don’t want it.
You’d have to get pretty freaking far from realistic in order to create a scenario where I’d rather be armed than not.