And people selling things are NEVER known to rig such product demonstrations to get people who want to be sold a fantasy version of self defense to buy their products. You have to learn to develop a BS detector. People who are selling you things such as vests, fancy 'hidden' weapons, mutilated military hand-to-hand things blown into full "martial arts" with a name of the month attached (Krav Maga is the current name for the favored form of Bullshido currently) will be happy to tell you how their item or art is the one single magic talisman that will protect you if the "SHTF". You will link to this and that and at the end of the day believe what you want to believe, I'll believe personal experience and the opinions of soldiers and policemen who use this stuff on a day to day basis.
I was wearing Class IIA just carrying an empty bag into a bank, got a few shots of 9mm, and got fractured ribs with one flatout broken. I suppose if my name were John (Rambo or Matrix) I could have drawn my sidearm and returned fire, but in the real world the man riding shotgun is who solved the situation, and he solved it without really doing more than firing it into the ground. The owner of "Second Chance" is free to claim that doesn't happen as much as he wants. It's right up there with people who swear up and down their "silencer" makes them into Specops warriors who are utterly undetectable and their commando knives with CO2 injection capabilities are sane "self defense" weaponry. If you want to believe such things, you'll believe it and spend thousands of dollars buying useless equipment.. and more power to you if you have it for the cool factor...
...but it has no civilian use of any kind, and even 9mm shots hurt enough to stop you unless you're also wearing trauma plates. A bullet"proof" vest simply does not do what you want it to do. It will not eat bullets and make the force of them magically vanish.
If you DO go around daily wearing trauma plates, perhaps you should stop living in fear, preparing for things that (if they come up you are going to die anyway) and prepare for things that might happen and you might have to face off against. If you're ever in any situation where you actually NEED that trauma plated armor, you're pretty much going for mutual destruction anyway.
Also, I refer you to the old "Box o' Truth"
http://www.theboxotruth.com/docs/bot16.htm
That's against class 3 body armor. Obviously, you'd want a rifle, but I sure wouldn't curl up into a ball and pee myself if people wearing Class III armor wanted to kill me and all I had was a pistol. I'd certainly be sure to leave or I was going to die and wondering how stupid I could possibly have been to get into this situation. But gosh I'd sure fire shots center mass as I ran like crazy to get away from the Russians landing paratroopers or whatever insane scenario caused this to happen. Perhaps I angered a clan of Ninja or something and between the constant zombie attacks I had to face off with 27 of them in a dark alley wielding UMP-45's. Of course then if I did somehow survive the coked-up body armor wearing ninja they'd then get me with the HIND they had waiting for me that I was too stupid to buy a SAM should I ever encounter one.
Long story short:
Quit preparing for things that won't happen: you aren't adequately prepared for them even if they did anyway, and you never will be.
....aaand having said all that... while I DO own a vest WITH trauma plates (got to keep one from the job that had split the fabric up front)).... I can't see any reason to ever wear it out and about, no matter how "high crime" the area is. It's just not FOR any situation I'll ever encounter likely enough to make it worth carrying around on a daily basis. At some point you have to stop fantasizing and start taking stock of your actual surroundings.