"There is a definite difference with it installed - no placebo effect AT ALL. If you put two identical cars next to each other and didn't tell the driver the SB was installed, had them drive the non-SB car first, then the SB car, he would definitely crap his pants at the difference!
1st gear is gonna take some getting used to - it was a bit yippy and there is a definite need to feather in the clutch a bit to even things out. 2nd and 3rd gear come on FAST. The thing I can say about this is that not only does the car drive differently, but it will change how you drive the car. I spent about 30 minutes tonight tooling around highways, back roads and parking lots. I am still giggling and grinning!" Review from Skyroadster.com