Mr. DuLac’s review published on Letterboxd:
A story of brotherhood among hitmen. Johnnie To has become the "go to director" for Hong Kong action movies now and this is a good example why. He's been compared to John Woo, but while Woo's Hong Kong movies had very stylized gun fights, I find that To seems to be more concerned with the build up to the violence. Kinda reminds you of a Sergio Leone western, which is funny because I think you could probably remake this entire movie into a western without changing much of the story.
One last thing: I think that the torch of "cool hitman in a trenchcoat and sunglasses" has been passed from Chow Yun-Fat to Anthony Wong after seeing this movie and Vengeance