For starters, I normally host the game, but if that makes me team leader and the game is over when I get killed, then some mission are going to be very short indeed.
It also seems that too much emphasis is placed on the team leader, with event triggers based solely on that person rather than any squad member.
Rural / non urban settings. I much preferred to open country maps to the city maps in GR, and was really looking forward to the new rural maps in GR-AW. I feel cheated that they aren't in the PC version of the game.
In the single player demo, controlling the other squad members just didn't seem to work for me. In the end they seemed more trouble that they were worth. I also noticed that one guy seemed to have unlimited ammunition as was able to stand there are fire continously for a few minutes without ever reloading or running out of ammo.
The demo didn't leave me leaving more, it was a big dissapointment, and form what I've read here since, I think that as a big coop fan the dissapointment would continue with the full game