I recently had the opportunity to play this game. I don't think it's worth a buy (rent, borrow, GameFly, whatever) but it has a story up there with (and possibly surpassing) Call of Duty 4: Modern Warfare. The thing with Spec Ops: The Line is story and characters, while the shooting is rather lamentable. It's completely designed to mess with your head and hate the character your playing as by the end. There are little touches that make you think you walked into hell with these guys, from the executions going from "killing me softly" to "I WILL GOUGE OUT YOUR EYES AND SKULL **** YOU!" On the bigger picture, you begin to question just everything as you go. I'm going to venture into spoiler territory now, highlight the black text if you wanna know badly.
Okay, the entire game starts out in what you think as In Medias Res, but when you get to the part in the game where it matches up you begin to question if it wasn't In Medias Res but rather a dream or just hell itself. While this is going on you are halucinating like crazy. But the biggest moment is when you see the effects of buring white phosphorus, use it anyway and wipe out civilians and then really question if you're actually helping people or just slaughtering them for the emotional high.
It's complex and surprisingly weighty. Again, worth a play, maybe not to own though.