i remember reading a comparison test on the filters (apexi, blitz, HKS and K&N)
and all gained around 14 BHP so difference isnt that much i know apexi was best for both filtration and power gain (best BY FAR for filtration, and 14BHP gain)
K&N was second best for filtration and was good power gain at 13.8 BHP
and actually HKS was worst by far filtration was SHOCKING and power gain was 13.6 BHP
so as for power gain you shouldnt notice that much of a difference
RellikZephyr