Hey Rage, I'm not directing this at you, more like picking on everyone who can only repeat what they hear. When one lacks first hand experience with something then said opinion is merely a reflection of the opinions heard. I've been playing with cars for 20+years, building, racing ect... and I have a pretty sound base with what works and what doesn't. K&N's filters work, they do flow better at high rpms. Even the filter cartridge they sell for the airbox flows better than stock. As for filtration, I'm not an engineer and don't play with particulate counters, K&N has them. If you want a performance increase, get a
insert brand here filter, whether it's K&N, AmsOil, AirRaid, whatever. But realise that you'll only see gains high in the rev range where flow is king.
Kids these days.... think they know everything.

At least that's what my dad said about me.