To effectively test the noise factor you would have to shoot two of the same arrows without fletching, one with the Sims insert, and one with a normal insert. The fletching are what make the most noise on an arrow so I don't know how much you would gain.

If it does help to minimize oscillation and vibration it could improve accuracy by allowing the fletch to stabilize the arrow sooner providing more consistency.

It is an interesting concept, but I'd like to see some testing on it before I fork over $15 for inserts.

Bry: That's my point. I don't think that there's any way that it's going to improve my arrow noise and accuracy near enough for me to spend the money for them.

I'd be more interested in the accuracy gains than the noise reduction personally. On the other hand, people have been winning competitions all these years without them so what little difference they may make would probably be wasted on an archer of my caliber. I doubt I'm good enough to notice a difference.