Coming back to this after having watched a lot more Mann films makes me appreciate this even more. The stoicism (i.e. loneliness), the professionalism (i.e. loneliness), the masculinity (i.e. ...well you get the point): all of these are hallmarks of Michael Mann's films. This is the most tragic depiction of the Mann dynamic because De Niro and Pacino finally find someone who understands them and it doesn't change a thing.
Also all the guns and planes and shit in this movie are really loud, and that rocks.