Agree about beauty---but I think the real genius of ggplot2 is the grammar. After using it, I think it becomes easier to think about data graphically and then quickly generate the visualization you have in your head. ggplot2 alone is a reason to switch to R.
Yes I actually meant beauty more in terms of the code rather than the graphs. Even the documentation is top notch.
It renders a lot faster if you change the x11 type type to Xlib, e.g. X11(type="Xlib") before displaying the plot.