If you think that R is The EnvironmentForStatisticalAnalysisAndGraphics but you do not think that Vim is The Editor for text files you might want to have a look at R Studio. It works on Windows, MacOS and Linux. I tried it out on my Ubuntu and it looks and works brilliantly. See more screenshots here. I will seriously consider it for teaching R.
My fingers are already addicted to Vim, so I do not plan to switch to any alternative interface any time soon.