The Sicilian is radical. The filmmaking here is clever, meticulous, & dynamic. It's pure cinema. It's not realistic but it paints such a detailed picture of the world& the political machinations of the period that it goes beyond verisimilitude, it becomes timeless in its themes. See something else if you like realism, this is a fever dream; a fantasy from history &romantic myth-making writ large in celluloid.
Dialogue so stilted it should be walking around in a circus; Sukowa's weird apparent dub-job; pointlessly pretty cinematography and that annoying swirly, 360 degree camera that try to distract from stiled dialogue. (like the cops talking in the car waving flashlights in each other's faces in "Desperate Hours") ...But Ackland smoulders with suppressed menace, and the film does improve when it later picks up pace.
In the second half, the story does begin to turn into the mess that everyone says it is. But throughout the entire film, it has some beautiful cinematography and shows that Cimino always had a great visual sense regardless of how weak of a script he was working with. This definitely an interesting failure, and as with all Cimino films, it is just intriguing enough to keep you watching or bring you back to it.