I think this is going to be ones of those "matter of taste" things.
My experiences were based on a kid (me) with serious play habits. My system would get at least 3-4 hours of play every day. I found myself needing to tweak the switches after only a couple of weeks at that pace. And once you start tweaking them, you will need to keep doing it, as every time you bend a piece of metal, it will fatigue it more and more. Until eventually, they will need to be replaced.
Another thing that will vary is the amount of corrosion the contact points get. If you live in a humid environment, this is likely to be more of a concern.
Don't get me wrong, I don't think there is a functionality problem, only a maintenance one. There's a reason why entire industries, including the arcade one, turned their backs on these things. And if someone thinks it was for a different reason, I'm all ears
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So if you are a tinkerer and/or you do more "building" than playing, you don't mind the extra costs involved and you want true retro buttons to go with the retro WICO joystick you are using, then stick to the leaf switch buttons.
But I would have a hard time recommending them to anyone else. That's just my opinion.
RandyT
*EDIT*
Maybe that "optical buttons" thing that popped up a while back is the real answer to this one