Y'all might remember last month I posted about the slight lack of midrange power in my XX.
http://www.cbr1100xx.org/forums/index.php?showtopic=36711
Last weekend I replaced the spark plugs with the new OEM NGK Iridium plugs, my XX still had the original NGK platnium plugs. I also replaced the air filter, which was noticeably dirty. In addition I did an oil & filter change (Shell Rotella Synthetic 5W-40) and replaced the PAIR system with Red J's blockoff kit. The throttle bodies had a slight coating of gummy varnish, so I cleaned them.
The result, a smoother idle, smoother midrange and little more power in the midrange. Nothing drastic, but definately noticeable, at least by my uncalibrated ass-dyno.
Thanks Guys.