Dose anyone have any experience with these http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=delkevic+exhaust+vmax&_nkwusc=delkevic+exhuast+vmax&_rdc=1 I was thinking about the 9" carbon fiber ones but I am wondering about what sound do they compare to, and most important do they rob hp...