Do these really make a difference? You can either pay £45.00 for a K&N or the Ramair/Pipercross for £32.00 Lots of people saying the throttle response feels better, and also its washable so I never have to buy another filter again. Anyone used these? Seems good value if you buy the Ramair one as you dont have to buy a filter every year. I am not expecting a +40bhp, but every little helps.