As a remake and as its own film

Rating: 7/10 (8 October 2006)

Scorsese's re-imagining of Infernal Affairs weighs in at a good hour longer than the tightly-paced original, and it is in this extra hour that Scorsese delivers a markedly different experience. How these differences play out in terms of quality is a bit more questionable. The new script writes in many more scenes between the film's two central characters of "undercover good cop" and "undercover bad mobster," attempting to fill them out with more profanity, grit, and add more "moral grayness." This is a process that I feel is successful at what it sets out to do by blurring the characters' senses of right and wrong more so than the original film, but by doing so has also erased part of what made these two characters likable and distinctive in the original work. While I enjoyed the complexity added to the characters, I do not feel that it went particular lengths to serve or strengthen the central storyline. As negative as it may sound, wandering off-topic from the original plot is where The Departed most succeeds. The storyline ventures off in considerably more directions than the original, taking much longer to hit the same key plot points that the original delivered at such a rapid pace. Herein lies the strength of Scorsese's film, as it remains a rapid and very entertaining picture despite the vast expansions and additions to the story. However, the key plot twists from Infernal Affairs generally feel uninspired compared to their delivery in the original film, and the closer The Departed gets to emulating the original, the less powerful the film becomes. As much as the climax has been retooled to make a tense scene even for those familiar with the original, the ending (which comes off as an oddly humorous combination of the endings of both Infernal Affairs and Infernal Affairs 3) is ultimately less impacting than that of the original film, and in my opinion failed to communicate what made the original's ending so good.
The film is alive with a very well-chosen cast (including Alec Baldwin portraying who was in the original film, the Asian Alec Baldwin), and includes one character being split into two, and another two characters being fused into one. Again this works to make The Departed a more chaotic, gray-zone film than the original, and while very watchable, lacks the clean and fast elegance of the source material. However, this is not to put The Departed on a "lower level" than Infernal Affairs, rather, it is a distinctly different film (good thing), but I still feel the original is a better movie (perhaps inevitable).
My initial impression is 7 out of 10, though I also feel on a repeat viewing I'd appraise it at a higher rating. It's a good movie, though due to my attachment to the original, I don't know if I'll ever jump into it as gleefully and willfully as say, Roger Ebert has.