I would only give it a 6 or a 7.

Lau gives ‘Departed’ an 8 out of 10
HONG KONG – Andy Lau gives “The Departed” ó an Americanized version of one of his movies ó an eight out of 10. The new Martin Scorsese film starring Leonardo DiCaprio, Matt Damon and Jack Nicholson was inspired by the 2002 Hong Kong crime thriller “Infernal Affairs,” which features Lau and Tony Leung.
“It’s correct that he gave it eight on a scale of 10,” Lau spokeswoman Alice Tam said, confirming remarks published Friday. She added that Lau dislikes the amount of foul language in the film and the fact that it has only one main female character.
“Infernal Affairs” is about a gangster who infiltrates the police (Lau) and a police officer who goes undercover in a gang (Leung). In the original, the two have separate love interests.
In “The Departed,” the undercover gangster in the police (Damon) and the undercover policeman in the gang (DiCaprio) both get romantically involved with the police psychiatrist played by Vera Farmiga.
Lau thinks “the effect of combining the two female characters in the original into one isn’t as good as in the original,” according to Tam.
She also said the veteran Hong Kong actor contrasted his approach to his role with Damon’s.
“He said he focused on his character’s psychology, and that the character didn’t look like a bad guy on the surface,” Tam said, whereas Damon’s portrayal showed his character as an obvious bad guy.