I've heard that it can make a 7-10 fps difference, that the bow would be quieter without the rubber tubing, and I'm interested in trying it out.

How do you keep your peep aligned without it?I know you can adjust the string so that it works out automatically, but I want something I can be a bit more sure of when the cards are down.

I'm looking at the T.R.U. Ball Speed Nok.
http://www.shootnhunt.com/catalog/JM/archery_supplies/releases_tabs_gloves_accessories/truball/2607349.html
It's designed for finger shooters like me, has a vane to keep the string from rotating, and since it's plastic, it's lighter and faster than the brass nocksets I'm using now. Is this a good way to go, or is there a better one?