This fabulous game really brings a feeling of tension and gives a real sense that you are on a covert mission - make too much noise or miss that headshot and your victims cry out alerting the guards and making progress much harder.
As a rifle shooter myself, I can testify to the realism of the shooting. Bullet drop is catered and perhaps winds affects (not sure on this though) - also if you have just run 200m and your breath is coming in short gasps then you cannot expect to place rock-steady cross-hairs on your target. The game also re-creates that fade of concentration you get when looking intently down your scope for too long.
Yes, there are some disjointed features e.g. the game will lurch from great action to a cut-scene with little explanation and you will find automatic game-saves cutting off the chat from your companion momentarily but overall, the graphics, sound and the action are spot on.
This is the only games that comes close the sniper mission in COD: MW.
Give it a shot!