@MAST: I agree. COD 4 was more difficult than COD 6. There is some parts on the game which are very hard (like Favelas, oil platform (with the smoke screen)) I spent a huge time to finish COD 4 on Veteran but only a couple of days for COD 6.
There was much less grenades on this game than the previous and maybe some times, the ennemies don't react the same way... There is the possibility of picking up a lot of weapons on the battlefield and the predator missile can help you so much for a really difficult check point.
However, this game is a very good first person shooter with nice interactives cut-scenes. Homer