"Professional" comes from the word Profession, which is what one does to make a living. Arrangers have made my living almost since they were first invented. I've never had one fail to get me through the night--250-300 jobs a year.
I do try to change keyboards once a year, but mostly for tax purposes. The PSR2000 is probably the least sturdy of all I've had, but even it has lasted me 18 months now, and is showing no signs of letting me down.
If I got drunk on the job every night, lost control and hammered it as hard as I could, it wouldn't last long though. (Now don't get excited, I'm not accusing anyone of doing that, but I do know that it's done.)
I don't abuse it or misuse it because I can't afford to be without it!
Don