I have two copies of hasbro's merge driver so I go the idea of wearing one down to a defensive state in right spin and the other in left. Currently they are partially worn and are in the gray area between defense and attack.
At the moment the left spin one the star shaped rubber is getting more rounded while the right spin one is retaining its star like shape.
It is cool to see how the driver will end up different depending on how it is used. It's ending result is dependent on the input.
Also the same might be true for jolt.
Highly Observant Hasbro Blader.