Piston coatings are a must for any engine build. If you are buying new pistons or you are going to be far enough in the engine to pull them out and have them coated then DO IT. The benefits of the coating, especially in performance applications, are a must have for protection.
Coating the tops of pistons protects and increases the life of the rings on the piston which reduces radial tension loss. Not a lot of people realize this, but the coating helps shield the rings from heat caused by improper burn of the fuel which creates hot spots. Heat kills performance so we want to get rid of it as fast as we can. Coating the tops of pistons helps with scavenging heat out of the motor. The thermal barrier coating on top of the piston helps to push the heat out of the motor.