On: Why I use ggplot2

Honorable mention for yhat's port of ggplot2 to python. http://ggplot.yhathq.com/

R together with javascript is the worst languagues I know that I still have to use. This can remove 50% of that list. I will check out this right now!

Do you have experience with it? If yes, do you prefer it over matplotlib (assuming you have experience with that)?

I have used it some, and my experience usually runs like this: (try simple thing) "Hey, it works!" (try slightly more complicated thing) "Too bad, this isn't implemented yet".