1) No one gives a shit about the Irish Mob; they are (or were) a bunch of small-time hoodlums in comparison to the relatively small Patriarca family of New England. What is that little organization Infernal Affairs covers again? Oh, yeah, the motherfucking Triads, an underground criminal society that shits on anything here in the United States.
How many films have been done on the Triads? A bunch, right? Well, how many films have been done on the Irish mob? Not very many. So, of course The Departed had a fresh feel to it because of the Boston setting.
Also, you put MOB MOVIE and SCORSESE next to it, then EVERYONE is going to care. It doesn't matter what kind of mob movie it is, if Scorsese's name is attached to it, people will care.
2) YOU must be on crack if you think any of the actors in The Departed gave a better performance than Tony Leung did in Infernal Affairs.
I thought his performance was very, very good and the best in the movie, but I still thought Matt Damon was better as that character than Leung was. Why? Simple... we never ended up hating Leung. He was a scumbag working for the Triads, but yet... it was impossible to truly dislike his character. Completely different story with Matt Damon, who you just had to hate in The Departed because he was such a slithering little weasel. Also, Leung did nothing in Infernal Affairs acting wise that was as good as Damon's scene in the elevator at the climax of the film. That was masterful acting on Damon's part if you ask me, particularly when Matt swings from defiant to broken, begging to be shot.
Also, let me say that Leonardo DiCaprio absolutely blew Andy Lau's performance away. Leo was able to show with his performance just how much anxiety an undercover cop must go through. Lau talked about how hard it was for him to his superior, but you never really felt him go through it like you did Leo. Moreover, if you compare the scenes where that character finds their superior dead after being thrown off the rooftop, DiCaprio's reaction is ten times better and more realistic, IMO.
I also felt that Wahlberg and Alec Baldwin's characters added a lot to the film as well. Wahlberg was just fantastic, while Baldwin was there for a little comedic relief, but showed a ton of intensity when the situation called for it.
However, all that said, I'll say I preferred Eric Tsang's mob boss character over Jack Nicholson's. I thought in The Departed Nicholson was way over the top, tried too hard to steal the show, and that his role ended up being more than it should have to be. He was selfish, basically. That was a big miscast by Scorsese if you ask me.
Now, another thing I'll give the edge to Infernal Affairs is the women. Not only was every woman in the film MUCH better to look at than that hideous, overrated bitch Vera Farmiga, but I also preferred the storyline with two women, rather than making it one woman sleeping with both rats. The only thing I didn't like there about Infernal Affairs was making that little girl Andy Lau's kid. That entire scene was completely unnecessary, and I think the only reason they added it was to give that pop star a small role in the film. I thought it hurt the film's integrity a bit. But regardless, Infernal Affairs definitely handled the lady situation every movie like this needs to have much better than what Scorsese decided to go with for The Departed.
3) Infernal Affairs kept things very stylish and suspenseful throughout its duration. Scorsese has never been a director known for style, and The Departed wasn't suspenseful in the least (without The Dropkick Murphy's Shipping Off to Boston, it wouldn't have raised my adrenaline one bit).
I completely disagree here, man. Leo's anxiety in the film was so well played by him that you couldn't help but get nervous for him and want him to succeed in his mission. Moreover, the two rooftop scenes, the post porn-theater scene, Wahlberg/Damon at the end, etc. were all heart pounding scenes.
Overall, The Departed in my opinion made a very good film into a truly great film. Sure, it has its flaws, but overall... I do feel it's a much more entertaining movie than Infernal Affairs and one that will stand the test of time more so because of its overall superiority to its predecessor.