Just got back from it, August always seems to have one kick-ass film come out (Fugitive, Sixth Sense) and this is this years. I am a huge fan of Michael Mann, and this film once again reaffirmed my faith in his abilities (after the confused and muddled Ali). I agree with whoever said if you shoot in LA, either hire or copy Mann. I also recommend seeing an early Mann work, Theif, if you haven't yet (Insider was one of my fav films from '99 also, my personal pic out of the 5 nominated Best Pictures that year).
My favorite part was Jamie impersonating Vincent and telling Felix to take off 35% for his fee, that and the Taxi scene, starting after Vincent shoots Ruffalo's detective till Max crashes the cab