There are also instances where performance parts can improve reliability. For example; The stock Yamaha piston has a 1mm offset piston pin that is offset toward the front of the engine (thrust side), which is designed to reduce the chance of cold start noise. This is done to reduce warranty claims from "mystery noises". It adds a fair amount of excess friction due to cylinder wall loading, and the factory cylinder coating is known to be soft compared to aftermarket nikasil.

Designing the aftermarket piston properly greatly reduces the wear cause by this offset. The factory piston is also known the fail at the pin boss in some conditions. I use the only piston that is made from 2618 material which is far stronger than the 4032 material used in other aftermarket designs.

Another benefit is the ability to design the piston with proper deck clearance. Bringing the piston to -.015" compared to -.050"(factory and most aftermarket), is worth about 2 hp over another piston rated at the same compression. Closing this "quench" area also improves efficiency and makes the engine less octane sensitive.

I know that it is difficult to read through what seems to be obsessive attention to detail on a single part like a piston, but if done correctly, it can improve performance and reliability.