Emacs has been the single best thing I have learned during the past year and a half. It has made me considerably more productive; org-mode, awesome syntax highlighting, using git is a breeze with magit, auto-indenting in ess makes my code look so much better and for R: r-autoyas which really speeds-up R coding to the max. I also do ssh management and directory management in it and I can send R codes to our cluster with a key-stroke. Looking back I think Emacs was really a good switch all in all... I just wish it would come with a decent text editor.