My bowtech has factory installed "speed nocks". From what I hear from my more experianced buddy they need to be in a pretty precice place on the string. and for no more speed than they add I wouldn't waste your money. Besides who needs 5 fps extra for bowhunting.
Sting Silencers........I love mine. Made by Martin. A good buddy of mine in New Mexico uses them and I wanted to try them out, so when i bought my Hoyt I had him throw a set on. Really nice.
The first thing a deer hears when i release the arrow on my Hoyt Razor tec is the sound of the the Rage 2 cutting its heart into. The string noise goes unnoticed...............