I moved my mother to Mint a few months ago. I have not had a single tech support call. She uses it daily. About a week in I asked her how it was going. She liked that printing worked more reliably and wished the scroll bars in Facebook were a bit thicker. Her printer used to show as offline sometimes in Windows but that issue has gone away under Mint. I was going to look for a theme with thicker scroll bars but she told me not to bother.

Granted she was a Firefox and Thunderbird user already so that helped with the transition.