AP Tuner or Tune the Car?
 

I am going to either have my car tuned at Hill's Garage, or buy an AP Tuner. I know with the AP tuner I can always revert back to factory settings at any time, and the tune is permanent, but I want to know if there are any performance differences between the two? Wich one is the best choice. I already know that there is a $200 difference (the AP Tuner is $400 and the Tune is $600), but which is better, Is there a performance difference?