I think this discussion has gone off the rails because of gun autism, which is fun and all, but I think it's better to stick to the needs of the user.
Plates are only supposed to do one thing realistically. Just protect your most vital organs, so when you get shot up, you have a chance of making it to the ER. Most of the time if you put 3-4 rounds of a rifle (AP) or not, you will very likely hit arms, legs, abdomen, hip. That is an instant down. Getting shot in the chest or head with a high caliber rifle is almost an instant death. With a handgun, maybe, adrenaline might keep you in the fight. A rifle round is another story.
imo, Null should just get a reliable AR platform, regular ammo, and a Glock/M&P 2.0. What's very useful and nobody talked about is shooting practice. A blue gun will pay for itself in range training. And you don't have to mess with a real gun in your house. And it's not like an airsoft one, where people might confuse it for one. Practicing and firing to targets is better than buying a retarded platform. It's the user, not the gun at the end of the day.