Evidently the recent patch has caused a lot of server issues lately, but eventually I was able to get in some good games. As with others, I was surprised at how relatively easy expert was for a decent team. We didn't finish it (A very clever smoker grabbed our gunner right at the end, and tanks stopped us about 4 other attempts) but we weren't getting manhandled as much as I had expected. The cooperative AI is surprisingly strong too, so if you're down a man you aren't hurting too much.

Witches are the best part of the demo. Very creepy, and near certain death for the unfortunate team member who disturbs her. Alas, the death is generally only temporary since she doesn't go after the rest of the team after downing one, but it can be awesome to watch.

The immediately obvious pros are that the action is very well paced and unexpected, you can never be quite sure where or when you're going to be horde rushed and this makes you look at every single section of terrain for it's defensive spots. Sound design is very well executed IMHO.

The cons are that, at least in the demo, it's easy. Graphics are the gray muddle you'd expect, and lighting is merely adequate (I don't have my settings cranked to max, just whatever it defaulted to, so take that with a grain of salt).

The best feature, IMHO, is the randomness. Sometimes you get attacked from a direction or in a spot where you've never been hit before and you just want to try to run forward or back to that place you know... where there's another horde waiting. Getting tank smacked is fun a few times too.