I think it's really sad that most people haven't seen IA before they went to see The Departed. Not to be racist or anything, but I saw a lot of fobby people there, and I knew instantly they they probably saw IA before, but as for the rest of the white people there, I was like "hmmm I wonder." I mean a lot of scenes you should've expected coming, and why all the gasps?
But that said, IA was directed differently, and has the "Hong Kong movie" feel to it, and I think it was just marginally better than The Departed. The Departed on the other hand was an excellent remake, and while it lacked some elements that gave IA thrill and suspense, it still did a great job in getting through the story.