this demo is jerky with normal (and some high) settings on my 7800gtx! but only in forests or near a few trees. Buildings seem fine.
Also there are a huge amount of bugs, like the AI, for instance some helicopters get blowen up and then the wreckage just floats in the air. And the soldiers in your squad will sometimes not be able to follow an order like 'get in humvee' they walk up to it and then start moving about like some sort of tard.
Also dont let an AI soldier drive, they cant see trees so will drive into them.
Also sometime when i'm loggin into servers i can see the game but all controls are frozen out...
I hope they patch this demo as even after all that it looks like when it works properly it will be outstanding