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.