Casio was never known for the best keybed saying that you get what you pay for and that is not a criticism because even the big guys in the industry have to cut the corners i.e new Yamaha MODX series especially MODX 8 have issues with the keybed because they put all of the Montage hardware in affordable package so something have to give in .
Casio does great job with super affordable prices in the case of MZ series is a steal I have Casio watch which cost much more than MZ so why complain you want the best quality buy Genos for 3000£ a bit more expensive than MZ 😁