adding k&n filter...

[The Big Red One]

forgot to add that I am now running BMC Race and also experienced what sixpack above shared:

My bike does feel much better in it's throttle response from idle. You can actually hear the difference with either of the aftermarket filters too. There is a noticeably deeper and louder tone from under the gas tank...less restriction of air flow into the throttle bodies.

I noticed the exact same thing, and have said it many times over the years in response to these types of threads. Its sad how an urban legend can get started and live on forever through the internet, just like in real life. But if you actually think about things analytically, and try stuff for yourself, urban legends don't usually hold much water. The only way any oiled aftermarket performance filter will reduce hp is if you over-oil it....which I did the first time I used a K&N. DON'T use the liquid oil, use the spray and lightly spray the filter, wait a couple minutes for the oil to spread, and re-spray the dry spots (if any), and you're good to go. You WILL get better throttle response, and according to Ryan Schnitz's dyno testing, about 1 1/2hp hp gain if I remember right. Plus you'll never have to buy another spendy stock paper filter
With performance mods its the sum of all the changes that gives you the big benefit in the end.
Depending on how much performance you want, and how much you're willing to spend, all those seemingly insignificant changes can add up to a lot. Just ask Brock