I was riding just to the right of a painted sharrow on a quiet residential street near me a couple of weeks ago when I got rage-passed by an SUV with a passenger yelling out the window for me to get onto the sidewalk. Some people can't be helped.
I do like the sharrows on roads that have them, anecdotally I feel that I am typically less likely to experience driver impatience on those roads as they help drivers to understand their need to share the road. I have wondered, though, the degree to which drivers may assume that roads without sharrows are not to be shared. It's an argument from silence, of course; probably the only way to confirm or allay this suspicion would be to poll drivers regarding what their road-sharing responsibilities are on sharrowed and unsharrowed roads. My guess is that most drivers don't even see them anyway.