Here what makes the Heat: Director's Definitive Edition so definitive. Michael Mann is best known for being an expert director of thrillers, including 1986's Manhunter - which marked the screen debut of Hannibal Lecter as played by Brian Cox - The Insider and Collateral. His one and only diversion into horror was 1983's The Keep, his second movie. The Keep found a group of Nazi soldiers trapped inside an ancient keep with a demon, but while it's considered a cult gem now, it was brutally recut by the studio without Mann's input and he seems reluctant to discuss the movie nowadays.
His most acclaimed work is undoubtedly Heat. This almost 3-hour masterwork primarily involves the inevitable collision course between Al Pacino's committed cop and Robert De Niro's (The Irishman) expert thief. The two men find they're not so different from one another and the film famously united the two screen icons for the first time. The movie has a rich cast of supporting characters too, who all feel fleshed ou, right down to Dennis Haysbert's tragic getaway driver. Heat also features arguably the greatest onscreen gunfight, where De Niro and his crew engage in a ferocious battle with police after a heist goes wrong.
Heat is a script Mann spent years developing and even made a dry run with the material in the form of 1989's L.A. Takedown, a greatly condensed version of the story that was shot as a TV pilot. Mann is also known for tinkering with different cuts of his work, which can be relatively minor - such as his new edit of 2015's Blackhat - or more intensive like the director's cut of biopic Ali. Prior to the 2017 Heat: Definitive Director's Edition, Mann had already tweaked the movie slightly for a 2009 release, trimming lines from a scene between Pacino's Hanna and his wife, and the line "Ferocious, aren't I?" following his famous "She's got a great a**!" outburst.
These subtle changes were to remove issues that bugged Mann about Heat, but its likely only hardcore fans would have noticed these changes. The same cut is present for the Heat: Director's Definitive Edition, but the major differences are visual. This 4K restoration saw Mann approach the movie's color timing like he shot it recently, giving the film more of a blueish hue to bring it in line with a lot of his other work. This makes the blue tones pop more, while the blacks - most notably in the final showdown between De Niro and Pacino - are much darker and more ominous. Like the aforementioned dialogue changes, only real Heat fans will pick up on the changes.
The Heat: Director's Definitive Edition also mostly ports over extras from previous releases, though it includes a 2015 Q&A with Mann and another panel hosted by director Christopher Nolan (Dunkirk), as he talks with Mann, Pacino, De Niro, Val Kilmer and other members of the cast and crew. For fans who own the film already, the Heat: Director's Definitive Edition probably isn't worth a double-dip. For everybody else, its the best edition of the film currently available and belongs in just about every Blu-ray collection.