I took mine to MAGFest where it got played on for four days straight, and seemed to hold up fine aside from one of the touch segments not responding. I've not had time to investigate or even play since then, unfortunately.
The ZhouSensor controller, like the arcade, actually uses optical switches - a foam block stuck to the bottom of the button plunger blocks a photosensor positioned below the button. In theory, it shouldn't wear out until it gets to the point that you're literally breaking the plastic on the dome's plungers, which probably won't happen at all in a residential setting. There are a few things that can go wrong - like the foam block falling off the button or the photosensor being slightly out of alignment - but it's all relatively easy to fix.
As for the mini controller, those buttons use the same type of switch found in
Hori's 30mm arcade buttons. You could buy replacement switches (
this Sanwa part should fit, but I haven't personally tested it and it might wind up being too sensitive) and it would just be a matter of popping the button out, popping out the dome by squeezing the plungers, pushing out the microswitch from underneath, and dropping the replacement in.