I have one that I installed about six months ago. It helped take my bike (a friend riding, cause I broke my neck) to 190 at the last Texas Mile. I love it and use it in my daily driving.
BUT.... I had to tune the kill time through several iterations, blew a fuse the 3rd or 4th 1/4 mile run (still don't know why), and now I get intermentant (sp?) false kill "hickups" at regular intervals of RPM. Maybe a ground fault, except that "does it almost every time at the same RPM thing".
But I still love it and think it's a lot better than the air shifters I see around.