What I admire about JRjr's work is that you can see in the finished page that he has taken the time to build the whole thing from perspective grids to backgrounds to sketched-in figures and finally to finished pencils.  Add to that his great sense of pacing, balance and placement and you just can't beat it.  All of those steps, I am guessing, probably contribute a lot to why you don't see wasted lines or "busy" areas that you tend to get from lesser artists who haven't taken the time to lay the foundations down.

All of which can just as easily be said about the other pros I admire: JB, Perez, Davis, and others...