c-rock - You'll know the Kevlar PASGT vest because it is camo, not usually OD green. Actually, the kevlar vests seem lighter and more flexible than the older vests.
rg00red - I stand corrected. I was under the impression that the Vietnam-era flak jackets were made of ballistic nylon. What type of aramid were they made of then? An aramid is only a broad category of man-made fibers, Kevlar is actually duPont's trademark name for the type of aramid fiber they developed. I do however completely agree that anyone who seriously feels the need to buy protective body armor should purchase police-style, NIJ rated soft body armor. It is lighter, more concealable, often less expensive (for used armor), and you can buy more protection with levels II or IIIA. www.bulletproofme.com is an excellent source for both armor and information about armor.
When buying used Kevlar armor, keep in mind that the fiber does break down somewhat if exposed to UV rays, sweat, dirt, etc. If cared for, Kevlar 29/129 lasts a very long time. Spectra and some of the other newer ballistic-resistant fibers are unaffected by moisture or UV rays but have a much lower melting point (if that's important), can be less flexible, and are more expensive. A trade off I guess.
SkaerE - I know this has been discussed millions of time before, but maybe these PASGT vests are inconsistent in quality? I swear I took a beat up looking one and shot it multiple times with a 9mm and a .40 cal....not a single round penetrated more than halfway through a panel! Kind of leaves you with a less than confident feeling about the quality control for armor our soldiers wear.
Go figure???