I have the Power duals with V&H Hi-Output slip on's, a high flow ac and PCV. I definately felt a huge difference in performance. The sound is nice, not too loud, but aggressive when you need it. I ride pretty hard and have not scraped the xpipes, have scraped my foot many times. If you lean hard on a slow speed, locked right turn, then yes you may scrape, just know that and don't lean so much, seriously, you have to be leaning pretty hard to scrape....