Me, Qpo, infernovia ("marredcarcass" in the video) and ksevcov tackle the second checkpoint of the first campaign on Expert difficulty (video recorded from ksevcov's viewpoint):
https://www.dropbox.com/s/y44tjbgza8fkb ... 6.avi?dl=1
Note that it took us 4+ hours of retries to pass this single checkpoint, and you are only watching our final, victorious attempt. The difficulty in this mode is glorious, and the game itself is also very good. Not sure if it's great yet, but I will let you know once, and if, we finish it. I definitely recommend it though, so gather three more people and give it a try if you haven't already (although for Expert mode you better make sure you have someone like Qpo in your team...)