Ive got one, thought it was the dogs when i got it, now im pissed off wiht it, its amkeing the car slow, my 0-60 times increased by about 0.5 of a sec wiht it on, and it stops my exhuast bubbling and popping, but for the £110 it cost me it was ok, it was at a time when i had little money.
Over about 4.5-5k revs it goes quiet, and its not overly loud, i want to get a k-tec one in the summer