One thing my better half and I both noticed; in places the film seemed to have been shot with poor quality equipment; my best description was that it looked like the video of Jack Ruby shooting Lee Harvey Oswald...anyone else notice? I wonder if this was done by the movie makers for a specific effect?
Someone else already addressed the technical aspects of the look of the film, but what kind of annoyed me was all the hand held camera work, and rapid edits. It has become popular with the advent of music videos and reality TV to work in this style, but for me it makes the movie harder to follow in some segments. And, I'm not just talking about Public Enemies here, but Public Enemies certainly is guilty of it.
Oh well, this fad to shall pass, but in the meantime I have to put up with hard to watch movies I guess.