However, the difference in key travel distance is very noticeable. I initially only applied the rings to half the keyboard, and I could immediately notice that the keys have reduced travel distance. This made typing a bit more tiring for me.
In static physics, Newton's third law tells us that for every action, there is an equal and opposite reaction. When your finger pushes the key to the bottom, the key starts "pushing back" against your finger with equal and opposite force. When your finger has to constantly deal with this force, it gets tired more quickly - this is what I think is happening anyway.
All in all, I would not recommend this product, at least if your keyboard is the MX or GX blue variant.