In 2011, I added an anonymous feedback form to
gwern.net
. It has worked well (116 entries) and justified the time it took to set up because it encourages people to correct various problems or tip me off on things. If you have a site, maybe you should add one too.
For the full writeup, see http://www.gwern.net/About#anonymous-feedback
I prefer ggplot2 too, but due to an ill-considered invocation of
fdupes
I yesterday trashed my local R installation, among other things, and haven't had time to make things right (I was busy with the Sheep Marketplace fallout and then writing up the post).