I have worn the gas mask and MOPP. No thanks.
I wore the vest for 5 months on gate duty at Benning, July thru November. It's hot and will cause dehydration, you have to keep ahead of it if you are actively working in 85+ heat. It's heavy, no matter what, and slows you down. It's difficult to sit for short periods, you basically slump against it and it rides up to some position you find isn't pressing against you. The edges are stiff - this was a fabric vest no plates. Your undershirt gets soaking wet in minutes after putting it on, and the overshirt for duty will get stains where the perspiration leaks into the fabric. There is no doubt you are wearing a vest, and it takes up a great deal of room which limits your carry options severely for CCW. Concealed meaning concealed, it intrudes on almost every body holster they offer. Exposed duty holster carry is almost mandatory.
In cold weather it's actually not that insulative and once it cools down you spend BTU's trying to make it warm because there's no insulation between you and it. It also forces you to wear oversized garments. It restricts your mobility leaning over or bending. For typical street wear in the neighborhood or around town, it's not going to offer anything other than inconvenience and discomfort.
Tactically it only incrementally improves survival. Since you should be behind cover anyway, your head and arms are what are exposed firing a weapon - and it doesn't protect them. All too often bullets strike under the arm where there is a large window for your shoulder to exit the armor, and the neck and head are completely exposed. It's predicated on the Center of Mass being the desired target - when you wouldn't shoot there if you see body armor in the first place. The better zones are groin, thighs, and neck, all of which have much higher levels of incapacitation when hit. And where precise tactical shooters practice hits. It stops mobility, which limits the opponents tactical response, and the arteries are much more targeted for rapid blood loss.
Serious, experienced force on force training suggests just wearing tourniquets at the major cutoff points to stop blood loss - uniforms and kit exists to do exactly that, so the wearer can continue the mission as far as they can, or at least expedite his extraction.
Vests are largely just feel good politics. Would I wear one going into a live fire area, maybe. The biggest push for armor has been city government and their insurer, or in the military, Congress and Mom. NOT the soldier, who is willing to pit his skill against others to prevail. This gets to plate carriers - which can be worn over the battle uniform, making them an option rather than required like vests. You throw them on when the threat level increases and it is more justified.
On a daily basis, no thanks, no body armor. Been there done that, it took all the romance about Second Chance right out of the first demonstration video I saw. It won't stop fire directed by an educated shooter aiming at more vulnerable areas. And for another thing, have we mentioned MERSA yet? No different than football pads, you have to keep them clean. Just more burden for the incremental return.
