People complain about two things: First, they complain about things that ought to work well but don't - "I can never find that option" "it crashes when I try

People complain about two things: First, they complain about things that ought to work well but don't - "I can never find that option" "it crashes when I try to do this" "it's counter-intuitive to need this" "the defaults are not sensible" "it takes too many button presses to do a common task" Then they complain about things that they want to be able to do, but can't - "it should support multiple timezones" "I want to be able to sync across my devices" "why can't I export it to another format" "I want more privacy control" The point is that no matter how much you work on the second list, if there is notable stuff on the first list your users will be unhappy regardless I am not convinced you can completely evaluate by yourself the importance of list A against list B. I really recommend polling users in controlled and well-thought out ways.