They have limited the damage a couple of times for me. Once when somebody reversed into it whilst parked and once when it slid down the road at reasonably high speed. The crank cases were scratched, so was the rear panels and the handle bars were bent but I think the bungs helped the bike slide and stopped anything digging into the road. They didn't bend or deform, just scratched and gouged up. I think it's worth it, I imagine engine bars are more protective, but how much better in a high speed spill is negligible because damage is inevitable in that scenario. They are heavier and you may not like them for their aesthetics either, either is better than nothing! My bungs were DHM, I think.