I dread to think of the noise and vibration with that thing fitted.
They're not too bad to be honest.
Fitted one to mine before last trackday, a fair amount of vibration when you are turning the engine over to start it but alright after that.
Plus side is that the car feels firmer throwing it around corners, the gear lever stays still under heavy acceleration and braking, and has stopped the exhaust banging on tight fast corners. Also £3 cheaper than the GSF crap rubber one.
Paul