I can tell you experience with mine from glockparts.com. I purchased the SS rod with factory weight spring for my G21 gen3. I tried for quite some time and I really didn't noticed any difference in accuracy or muzzle flip. Maybe tungten can have better results since it's heavier. I did noticed it was harder to get the slide apart with the SS rod after shooting. I have mine for sale since i don't see any advantage of having it unless i want to customize it.