When I bought my bike last December, used, it had SE II's and a stage one installed. It ran ok but stumbled at certain rpm's a bit and backfired between shifts on occasion. I thought it had good power. I was wrong. I had my dealer, which I think is probably the best on the planet, install a power commander and dyno tune it. They dropped it off at my house this morning. It was raining a bit and windy but being an idiot I couldn't resist. Holy smokes.................I could not believe the difference. No more backfire, no more hiccups, it runs smooth in all ranges and man does it have more power. It sounds a bit different, can't quite put my finger on it, maybe a bit louder or deeper but no more pops and stutters..........YAY!!!!!!!!!! The dyno readout sheet showed a bit over 9% increase for both hp and torque. I have no idea if that is good or not but the manager of the service dept. said they were good numbers and I am absolutely thrilled with the way it runs now. I know, this isn't earthshaking news but I had to tell someone. My wife just shakes her head and goes back to reading her book. Everyone have a good day and ride safe.