Originally Posted by NitroVein

Yes they turn the same rpmīs, but they could turn at different speed.
It all depends on how big the balls are compared to where they they orbit.
If they turn the same rpmīs and speed then the rear balls must be bigger(because they have a greater distance to travel, due to larger diameter).
Bigger(larger diameter balls) means moor mass, and ceramic weight are around 1/4 compared to steel (if I donīt remember it wrong).
There for if you only want to run one ceramic the rear makes the most difference when it comes to mass, and mass is what takes time to accelerate.