Of course they increase performance. They might not give you the peak figures etc, but look at any rolling road graph and you'll see how they fair against a stock intake. For you to say that, I guess you've never done it
Its kinda well known round these parts that K&N Don't quite deliver the good as far as BHP is concerned. It more about the noise. On quite a few cars they have actually caused a decrease in power.
PNL I belive is GSR inducted with a remap he does know his stuff!