Depends on what you are trying to accomplish. On a .45 cal, uncompensated pistol, the Harrts is designed to reduce muzzle flip, which is why it does not work on compensated guns. Whether it reduces it more than adding a solid guide rod of the same weight is open to debate. As the other poster suggested, some people do not seem to notice a difference, but I have Harrts in most of my .40 and .45 cal pistols. I use Sprinco in all 9mm pistols, and some .40 and .45's. The Sprinco reduces the slide velocity over the last bit of slide travel, spreading the recoil out over a longer period, making the recoil feel lessened.