The Task Force Spartan use the JPC. We load them to real standard. No complaints on the shoulder straps. I did notice that they dig a little with "real" SAPI plates. But not to the point where I feel like removing it. If you use foam plates, it won't hurt.
We are about 15 guys that use it. We beat the shit out of it. We even dragged a man by the shoulder strap and it held just fine.
This is the copy we use. It's the best copy on the market.
http://www.shootercbgear.com/advance...tion=1&x=0&y=0