The original Switch (Omron D2F-01F) and its slightly heavier cousin (Omron D2F-01) are both rated for low voltage/amperage use (100mA max). Because of this, the contacts are plated with gold. The other 2 switches which are mentioned in this article (Omron D2F and C&K ZMCJF7P0T) are meant for switching larger 3A currents. Because of this, their contacts are coated in a silver alloy.

I say all this because the silver alloy can oxidize over time and prevent reliable contact. That alloy depends on the occasional spark from the higher current to “clean” off this oxide ensuring contact can be made. Using a silver alloy in a low current application will not provide this spark and may prematurely fail. Gold, on the other hand, tends to not oxidize and does not require this “cleaning”.

Long story short, I recommend either of the 2 gold plated switches in this application. Use the original (Omron D2F-01F) if you like a lighter button press or the other (Omron D2F-01) if you prefer a heavier button press.