OK Min, I'll bite.
The chances of a home invasion being focused on me personally is remote. I am not a high yield, low threat target. I do not have high dollar jewelry in my home, nor large amounts of cash. I have guns, but so do my neighbors. There really isn't anything to make me into a target. I might be invaded by a drug addict looking for something to steal, or a kid looking to make a name for himself with a gang. There might even be the possibility of an invasion in a fit of rage I suppose. I might even be a target of opportunity for a serial type invader.
I do not, however, expect any well prepared career criminals to be focusing on my home in such a way that they will need body armor. Most home invaders don't wear body armor. Most armed robbers do not wear body armor. Most criminals as a whole do not wear body armor. Why is this? They do not expect to get shot at. They often do not expect opposition at all. If they do, they go to a target that has less risk, or at least enough benefit to justify getting shot at.
I suppose there is a possibility that a home invader would use body armor..... There is also a possibility that they will use flash bangs, or maybe sneak in while you are away and remove the sear from your pistol, place it back where it was, and then invade your home that night. Anything is possible, but not everything is likely. You cannot prepare for everything, so you must choose the most likely scenerio.
Looking at past home invasions though, I think there is a high probability that no body armor will be used, that there will be one or two perps, that I will be awakened from my sleep, the house will be dark, and the confrontation will be over in under a minute from the time I awoke. I'm thinking a shotgun would be the best tool for the job.
I have no mob affiliations and no bodyguards. I am not a felon on the run, nor am I a cop, and it is not common knowlege that I have guns in my home. It is certainly not common knowlege that I sleep with a shotgun at hand. There is simply no reason a person would wear body armor to invade my home.
When criminals begin to use body armor more frequently, I will change my tactics. Until then, I'll stick with the 12 gauge. The numbers say that is the way to go.