I saw this movie when it was released to the  theaters in the '70s.  In New York City.  In a moviehouse in Times Square.  The theatre  was full of blacks and there were roaches running up the walls and cum all over  the seats and this is the  only way to see this movie:  Sit right in  the  middle  of  the theater  of action  while it  is all over the screen.  I walked out with my friends after  it was  over into the late afternoon sun and none  of us  needed to say anything.  This totally is a New York movie about going insane in New York City and cathartically divesting yourself of the whole mess you find yourself in in a very lethal way and  getting away with  it, then returning  to normalcy, having been cleansed of the demons which drove you into  madness in the first place.  Heavy duty.  Love this movie.