I picked my bike up yesterday and had my first ride after the filter was installed, only other performance mod so far is exhaust which is only good for 3.5 hp to the wheel. I couldn't believe the difference in the pull of the bike yesterday, it definitely is a noticeable improvement.... is that stock filter that restrictive?? 1st through 4th gear was much "snappier" and the bike pulled harder no doubt but the real noticeable difference was the 5th gear roll on when I hit the highway. Before to get any kind of grinning acceleration I would have to drop into 4th and hammer it, yesterday when I hit in 5th it was a dramatic difference! I was grinning ear to ear. I have put K&N's on every bike I've ever had and it pepped them up a little but nothing as drastic as this bike. I was pleasantly surprised! I can only imagine after I install my torq loops and Bazzaz controller how hard this bike is going to pull......With the K&N, exhaust, & loops I should be at a 9-10 hp & torque gain at the wheel. The Bazzaz will be another 8-9 in both torque and horsepower. When all is done I should be adding 18-19 hp & torque to the wheel....this baby should scream! Stay tuned....it's about to get real up in here! lol............. Oh did I mention the NOS shot in the works......... For those who added the K&N did you experience a similar result or is my "butt dyno" telling me stories????