I'll be doing some tutorials in the next few weeks on it so keep an eye out if you are interested. It is very powerful, very quick and easy to use and one of the great features is the level of documentation that is available. Every add on package has to be documented and most include easy to follow examples.
In the beginning it was more difficult to use but in the last few years an IDE R Studio has been developed which makes it very easy to use.
I used R Studio for the course, but I didn't get as far as the graphing.