I have all three. At some point or another all three have performed the duty. But currently, and I believe ideally, its a Remington 870 12ga.
For the arguments. No one is going to get close enough to me to disable my hand if they have to walk through a storm of .32 caliber OO buck pellets to do it.
I don't care if they hear me rack the slide. I sure hope they do. I hope they hear it and run like the devil's chasing them. If I don't have to shoot them, more the better. Just because I'm willing to, does not mean I want to.
The distance from nose to muzzle is not going to be that much farther with a shouldered shotgun and 18" barrel than it is with a 1911 in a good shooting stance (especially for me, I have very long arms).
The sounds are going to be muffled by the adrenaline you have pumping anyway. I'm not sure what expert witnesses call this phenomenon, but its kind of like tunnel vision with your ears. Choose the tool to do the job, not be the quietest.
For the benefits. Birdshot, buckshot, slugs. Anything coming out of the business end is going to do the job.
In the dark, accuracy is not exactly easy. Shotgun has less over-penetration (if you live in an area where that is a concern, such as an apartment). You do not exactly have to be a sharpshooter with a 12 ga. OO buck shotgun. Each shell has several opportunities to end the situation.
The gun you have is better than the gun you wish you had. So use what you have. If you have all three, the 12 ga. pump is best suited for this particular task. I suppose I should add a caveat and say "In my opinion"...