Got the new lightened pulley today. Was expecting noises and vibrations as you said...yet there is nothing. Absolutely no extra rattles or noise. Has changed the way it powers down a very small amount, mainly in the higher revs. But it looks cool so it was worth the money. Should've dynoed it before and after to see the changes, if any. It might not feel that much different to you, but it feels different to your crankshaft and internals.