I agree more with arsaib than wpqx. Although I probably would go even further, and call it a failure. For me it failed in the acting department (mostly very unbalanced performances, probably due to "green-screen"), and a script that seems more like a best-of of Miller, than a coherent depiction of the complexities of Millers work. I haven't read all of the stories from the World of Sin City, but imo the film rarely manages to come even close to the comic-books. Rodriguez doesn't really seem to care about his characters, their surroundings and the story. What he's interested in is the mostly the atmosphere and feel of Miller, but he seems to forget that those things are closely connected to the factors he leaves behind on the roadside.
The visuals are interesting, but are not put into service. They stand more or less for themselves, being thus rather showy and pretentious.
Though I'll give the film another - proper - try sometime in the future with the extended version and the right audio (I saw it dubbed )I'll probably at best end up with arsaib's position. 
Imo dismissable and a disapointment.