An upgraded piston may increase fps and consistency, but in small amounts, sometimes even hardly noticeable.
The one thing an upgraded piston will significantly increase is durability. Because of this increased durability, you have peace of mind that the piston will not break and this will also allow you to use heftier springs.
The piston head is required for proper usage of that piston in particular. It is meant to absorb shock so the piston itself won't be under a lot of stress (i.e. longer piston lifespan.) In terms of reducing vibration, it too is hardly noticeable.
The one thing an upgraded piston will significantly increase is durability. Because of this increased durability, you have peace of mind that the piston will not break and this will also allow you to use heftier springs.
The piston head is required for proper usage of that piston in particular. It is meant to absorb shock so the piston itself won't be under a lot of stress (i.e. longer piston lifespan.) In terms of reducing vibration, it too is hardly noticeable.