An excellent retrospective on one of my all-time favourites. I agree it probably does fall short of greatness from an objective perspective (it's not The Godfather or Goodfellas) but I absolutely love the film, and have done ever since I first saw it in early 1994 as the sole attendee of a matinee showing when I was a student. It's incredibly absorbing and satisfying on many levels.
One of your key points here, about De Palma's flashiness for once being in service of the narrative, is one of the reasons Carlito's Way ranks in my De Palma top three (alongside The Untouchables and Carrie). Personally, I'm not a fan of his Scarface remake. It's slickly directed, but so utterly horrid and excessively violent to no good purpose that I find it a rather wretched viewing experience.