i havnt heard it personally but one point zoomers stresses is no in-cabin drone. personally i have the b&b and its pretty quiet, there is still a slight around 1800-2000 but on the whole its quiet as stock inside the cab, outsid eits a bit louder. as for the cutout and backpressure, if you look at dynos on other forums, at WOT they provide a hp gain over any aftermarket exhaust. sometimes only a few horses and lbs of torque. at cruising rpm im betting there will be a slight loss in power. with that said, there is a very loud drone in the cab with them fully opened which i cant bare but for wot runs its music to my ears.