RE: Pass the salt... MAJOR kudos to the Muzzy Zero Effect rest!
Geronimo,
I heard a friend use this phrase once, and I think it a most appropriate answer to your question: Quieter than a church mouse peeing on a cotton ball! [8D]
It really is. There's just NO noise with this rest.
Again, the two best points -- in my mind -- that it has going for it, are:
Number one, by far --NO part of this rest comes back and slaps the shelf at the firing of the bow. There is absolutely no need to put any kind of moleskin or other sound-dampening device on your shelf to keep the launcher arm from banging into it. That's why this rest continually takes top honors when it comes to independent test reviews.
Number two is the almost-full containment. Though Muzzy provides the nicest arrow holder I've yet seen from any manufacturer to be applied to your bow's shelf, there's really no need. Unless you're trying to shoot your bow upside-down, there is simply no way the arm -- what looks like that big "hook" -- will not pick up the arrow and allow it to fall perfectly into shooting position.
The only downfall at present time is the fact that it won't fit every new bow out there right now... and that's something the inventor of the rest and I are talking about moving forward -- at least on Bowtech's bows.