Before I got into AR's, I was originally researching pumps for HD....but a Palmetto State sale caught my eye, and several AR's later, I'm still pump-less. The more research I do, the less I'm inclined to get a shotgun as my primary HD weapon right now. I stress "right now" because from all of my research, I do remember an article that talked about slings...because you might need your hands to usher (or carry) little ones out of harms way. I have little ones...so the main drawback of the (pump) shotgun is that it always requires two hands....and the noise. If something happens, I will have to pick-up crying kids that won't want to move. But, that shotty is probably the most reliable, and per trigger pull, the most effective. The limited ammo does not bug me that much because realistically, how often do people empty shotguns in HD situations? It is also probably the least likely to kill a neighbor. It is the only one that can go from taking a deer to taking a duck simply by using a different shell in a pure SHTF situation. Maybe in a few years....
I actually think I'm trending towards the AR pistol in .300....assuming I can find the right ammo don't won't go through every wall in the neighbors house. An 8.5" barrel makes it compact and easy to handle in tight spaces, but a big benefit is that it can go with me anywhere. I also like that I can put a sling on it. All of my current slings have an elastic section, and my 10.5" and 16" have Magpul K2+ grips (more vertical), so those weapons stay close to my body, and they are also meant to be held high and tight. I have to extend them out against the pull of the elastic when I shoot. The vertical foregrip on my 16" is almost as close to the magwell as possible. I like to keep my elbows tucked in for a smaller profile. I currently have no reason to ever shoot at something more than 30 yards away, so that is how I practice.
A full-size pistol with a light seems like it would work, but I'm trying to think of a situation where I would want a full size pistol with a light, over my Shield 9, or a .300blk pistol with a light. (I almost got suckered into another sale a few weeks ago......Shield 2.0's with a integrated lasers)
Right now my 10.5" AR pistol in 5.56 is my home defense weapon....but I can't even imagine how loud that would be indoors...or how bright the flash would be in the middle of the night. I guess I could just shoot a round into the ceiling it would act as a flash bang.