ive only ridden a piped trx and yfz, they are nothing special, alot of instant torque, better traction off the line in the dirt, you can get them outa the hole quick without alot of tire spin easier than a banshee of course, get em in the open , on pavement, on grass,and the banshee is just as fast as a piped one of them if not faster on the topend, im only talking about piped/k&N filter here, never rirdden or ridden with a ported/hihg comp piston, camed one though but i bet they are sweet. id really like to get my hands on a KTM 525xc