It's a good keyboard comfortable to use but is too fragile for use professionnel.Je am developer, so I am using the keyboard greatly because I hit hundreds of daily lines of code (in typing mode). After a year and a half, maybe two years, the most used are started to fade buttons (the E, S and SHIFT in loccurrence), even here nothing major since I know type without looking at the keyboard. More recently, it is the letter Q, which jumped while the keyboard less than three years. My keyboard is unusable. I have a colleague who would came after less than a year of use, apparently his finger slipped under a key, which blew it up.
It's a shame because it's a really comfortable keyboard, I no longer feels pain in the phalanges in the evening since I use it. It should be just a little more robust to avoid change every two years.