I have owned both and still have the ACS limbs. The Epic was quieter to my ear or at least a better pitch but not that much not to go to the ACS that is a good bit faster and a little smoother to pull. If you are not that interested in the high dollar high performance limbs the Epic was as good a limb for the price as any I have shot. I would also have to throw in the Black Max Extreme limb that I just shot last month, very good limb for the money.