It works more for a manual mustang more. but essentially Ford has the pedal set low for safety not to over throttle the car so it hits the ground so you don't neccessarly get a full throw. When you raise it, it tightens the throttle linkage slack and allows you to get a full throw and quickens throttle response. turns that sluggish start to a more responisve start. feels like the car got a lot lighter.
for manuals it will allow you to do heal toe shifting, which is almost impossible with the ford configuration.
So basically, quicker throttle response, full throw, heal toe shifting.