Someone quoted a report where the police miss their targets 89% of the time. (??)
Yes, that's a true stat. Cop friend was telling me, real life with moving targets is a lot harder than going to the range. Very little time to aim, thus the "Pray and Spray."
Regarding vests, won't stop a high velocity round but will turn it into a low velocity round... Basically, for example, a 223
cal round is no larger in diameter than a 22, but the speed produces a shock-destruction that is about 2 inches in diameter making it a lot more lethal. So, if a vest drops the velocity so that you only have a small hole through you, there is less chance of a major blood vessel being taken out, and therefore your survive-ability increases greatly.
So, bottom
line, if it is a high risk situation, the vest can really save you even if high velocity rounds hit you. Still a lot of luck involved, but anything to increase the odds sounds good to me.
Of course, your best option many times over is GTFO !!!