Looks great, there`s no doubt it could be an enormous help but I`d like to see something designed to deter the thrust. I`ve heard there are stab-proof vests out there, I just don`t have experiance with them.
I do have experiance with knives though. I worked 7 years in the custom shop at Busse Combat Knife Co. After the invation of Panama (yes, I`m old) we got comments from customers in the Spec/Ops community who said thier knives had gone through Kevlar vests "like going through an aluminium pop can." Still, being a knife guy from way back I`d love to get ahold of something light and concealable that offers real protection.