@kazriko @Zergling_man @ademalsasa Regarding pain, that's why I switched--at the recommendation of my doctor.
I was a competitive piano player in addition to sitting at a computer all day, and noticed some numbness in my left wrist and elbow. My doctor thought it might be RSI and even early signs of carpal tunnel, so he suggested I find a new job and stop playing the piano.
I couldn't do either, so he mentioned some patients had success switching to Dvorak, so I gave that a try. It worked.