Crysis is supposed to be a game about movement. That's what half the trailers were going on about, isn't it? But the MP design actively discourages movement. If you sprint, you lose power. If you lose power, your armour mode is less effective. Meaning when you run round the corner and meet a guy crouched in a corner, he'll come out on top, because he has a full power bar and can eat twice as many bullets as you.
As I get to higher levels, I've been noticing this more and more. It seriously ruins the game when the way to win is to hide round a corner with your finger hovering over the Max Armour button.