frankly you get what you pay for, yes Piper is slightly more expensive but they are the best systems on the market, the quality of the system is far better than milltek when you look at the 2 side by side, the turbo backs have got wider bore downpipes, and the sound is better, obviously time will tell how they last but since you get a lifetime guarentee with Piper rather than the 2yrs years you get with Milltek frankly, it was a no brainer.