Seems like it makes the bow a bit faster, as it stiffens the limb while lowering weight. It seems to help longbows more than recurves, not sure why. Some people claim that it creates a different kind of sound when the bow goes off, and that deer, et al., hear this pitch more intensely than the one created by wood/glass bows, creating a ducking issue when hunting. I guess it all depends on whether you think 5-10 fps will make a real difference in your ability to hit things. I personally wouldn't pay a lot more for it if it was an option, but would probably get it if it was a fairly reasonable option. Good luck on your choice, Paul.