"The FOC of a NuFletch-fitted arrow will be closer to 3-4% Front of Center."
The website then goes into a discussion of how this actually improves flight because of decreased occilation. I have never heard this discussion before, so am not sure I believe it. Have always been told downrange accuracy is improved with higher FOC. The increased weight will probably increase penetration, but probably less so than if you added the same amount of weight to the front of your arrow. My fletchings are 3 degree helical, so I'd probably lose stability with the 2 degree and decreased FOC. The idea is a good one, they just need to find a way to decrease the weight. Of course then you would have 3 things screwed into your arrow that you would have to occasionally tighten up while target practicing.
Don't know why they don't come up with the shrink wrap fletchings that are helical...shrug.