I received my set today, but will need to wait a while for the CD player to complete its own break in before I can comment on the component.
One thing though: "quiet" will be most noticeable if you have a component whose noise floor is higher than the component lowering that floor. It may take longer to determine the benefits in one's system if other colorations, such as the room, are not attended to. It will be hard to hear more depth if you have a 125 Hz bass lift rolling around your room.
I haven't noticed the improvement yet, but as I said, I just found them on my back porch 10 minutes ago (UPS doesn't bother to leave notices any more). I will also be interested in "seeing" (aurally speaking) the difference between them and the ceramic cable lifts I have!
What a wonderful hobby we live in....if it doesn't make us neurotic, that is...