First accepting what Gunrunner said that a Sportster will "smoke a bagger," I get good reliability and decent performance (plus a lotmore comfort out of my 2001 RKC)with a Screaming Eagel Air Filter, Vance & Hines Dresser Duals, Samson Ovals and a Screaming Eagle Race Tuner. Although expensive, aScreaming Eagle 6 Speed is a nice top end performance addition too!

 

I'm moving forward with more engine mods on my '01, so the Stage II download ($ 140.00 at dealer) won't cut it. I'm adding a PCIII-usb to allow tuning the headwork and different cams. The Stage II download will "allow me to limp home" should the PCIII fail, so it's of some value. If I did it all over again, I'd just go straight to the PCIII-usb. The expensive option is the ThunderMax MM conversion, around $ 1850 retail.