I think youre deceiving yourself if you think someone wearing a vest is just going to stop what they are doing and run away when you shoot them.
While there is some blunt force trauma, its generally not as bad as youre making out, and usually will not stop the person being shot, from making instant and effective return fire on you.
Check out Rick Davis's video, "Second Chance vs the Cop Killers". It may open your eyes to a few things about vests and what they can and cant do, and there is also a lot of other stuff in there thats pretty entertaining too. He has a number of cops in the video giving testimonials, that were shot while wearing his vests who survived, and many of them instantly returned fire to do so. Rick started Second Chance, and shoots himself and has others shoot him, while hes wearing one, on numerous occasions, and he responds instantly afterwards by picking up a gun, and shooting targets nearby.
Other than maybe some of the old KTW rounds, I dont know of any 9mm that will penetrate a 9mm rated vest in the "protected" area, +P+, "SMG" or what.
If the person in your house is wearing armor, chances are, hes there for a purpose other than just stealing your stuff, and if he is, I would assume youre already on board and have the proper weapon close by.
