The thing with Miller vs McFarlane is that Miller knows how to draw and McFarlane doesn't. Both are very stylized but if you don't know how to draw then you can't stylize as effectively. Knowing how to draw something is a matter of understanding it. When McFarlane draws figures he makes up a lot of the anatomy. He wants to draw a hyper muscular look but he doesn't understand the anatomy so he has to fake it and it detracts from the work. Whereas Miller's intense chiaroscuro work in Sin City reveals his draftsmanship, as doing that heavy lighting is impossible if you don't understand the forms.

As far as aesthetic goes, Miller has had this to say:

It can be ugly at times but its power is never diminished.

One of the most interesting things about Miller's work is the inking. There are three maker inkers in his career: Klaus Janson, inker on Daredevil and Dark Knight, Joe Rubinstein, inker on Wolverine and himself. Janson used a very energetic and almost chaotic line, while Rubinstein went for a much more conventional approach. The weirdest thing is that Miller inks himself with a very dead line with little line variance. I wonder how Daredevil, Wolverine and Dark Knight would have looked if he had inked himself with that dead line, as his self-inked work is usually the stuff that is most often referred to as ugly.