I recently bought another Magpul MS2 sling and it turned out to be a fake. The vendor didn't even realize it was a fake until I informed him, he promptly refunded my money and told me to keep the sling.
The packaging on the fake:
The give aways:
The adjustment buckles
Gold on the real Dark Earth, Black on the fake:
The rivet on the real is solid, hollow on the fake:
The attachment hardware is painted versus anodized:
More hardware differences:
Real on the left, fake on the right:
Tag on the upper is the real, fake is the lower one, notice the bleeding of the colors and the lack of a "trough" for the stitching:
The strap material is thinner on the fake and is improperly "sealed"
Real is on the left, fake on the right: