If you are Ruby On Rails Developer, RubyMine is great choice of IDE. It provides good integration with rails so that running rake tasks, generators, bundle install all can be done from within the IDE. So using RubyMine it decreases extra time to go to googling syntax for Ruby code and making developer more productive.
RubyMine is specifically for Ruby On Rails so it is more focused and having more syntax autocompletion and other tasks automation with good code debugging skill. So, for particular Ruby On Rails project development it is much more advanced and effective than any other general IDE like Visual studio and Sublime Text.
sometimes it feels slow down system because of using RubyMine as it requires more memory and power.
RubyMine is great choice of any Ruby On Rails Developer as it reduces time of project development by providing lots of inbuilt functionalities like autocompletes syntax running rake task, git integrations and many more