Some tuners are just better with one tool than the other. No particular reason a bike should run significantly better or worse with one than the other though. If you don't mind buying a SERT and your guy promises he can tune with it than go for it. If you'd prefer to stay with the Power Commander you already own it might be worthwhile to send a PM to Howie. If memory serves he had a tuner in your general area very competent with the Power Commander.
he actually told me several things that the race tuner does that the pc does not.
my problem is that i am a layman and really don't grasp it.
he did say the bike runs fine the way it is.
he tunes alot of the crotch rockets with the pc, so i don't think he is more comfortable with one than the other.
i would really like to know about that zion sensor.
thanks for your reply.
lou