Been playing some of it today, with mixed results - I did have to switch back to Gamer on my gaming laptop, but it didnt help much. Game played really fluid after a short while. Won a few rounds as number one, came out last in one of them. Skyline with a sniper rifle was my worst idea though, so switching back to Soldier helped.
I like the guns, the graphics are very impressive (Though its crazy this is only a DX9 port-of-a-port demo..), and the game would run a whole lot better with the DX11 options available. Both my laptop and PC support that for a reason.
Weird decisions but a good good taste of Crysis 2. I'm overall pretty positive.