2droptine, very good point and my concern exactly. I can say that right now I have the bisquit on both of my bows and if it wasn' t for fletching wear I' d say it' s as close to perfect as you could hope for.
The differance with the bisquit vs other containment rest is that it grabs all three fletching equally, straightening their flight path as they go through it. That might sound silly, but it explains the ease of bullet holes when paper tuning one of these rest. Just center the rest with the sight bolts and the centerline of the bow, make sure your knock is where it should be and you' ll get bullet holes. Perfected tweeking comes from group size down range.

One bad thing about the ease of bullet holes with this rest is deception in thinking all is good with a pefect hole. A coworker of mine went to a proshop where the salesperson papertuned his bow with a bisquit and then sold him some expandables and said he was good to hunt. Two wounded animals later and he has sworn off deer hunting with a bow. MORAL= papertuned doesn' t equal perfect arrow flight.