The Natural Keyboards [0] have been getting less and less durable as the years go by. My first one lasted for ~five years. My second, two or three. My third is less than a year old and already suffering from intermittent failure to register keypresses, as well as surprisingly rapid breakdown of the faux leather material that covers the bottom portion of the keyboard. (The faux leather breakdown is a first for me... all the other keyboards suffered mechanical failure long before I saw any sort of wear on the bottom portion material.)
[0] Specifically, the MSFT Natural Ergonomic Keyboard X000 models that have the stupid, useless zoom slider.