I didn't get enough of a taste to enjoy it. They didn't give us very much to play with; it felt like I was playing another added campaign, like Crash Course, or a player-made map, but it still felt like Left 4 Dead (1). The limited option of melee weapons (though, the machete is rather nice) deflated my enthusiasm a little bit. I liked the soundtrack, though, and the new characters are definately loveable (I favoured Ellis for some reason ^_^)
But basically, I got bored with it real quickly. I ran through it three times to test that AI Director 2.0, but to my dismay, the level didn't change at all. But who knows, maybe I just got him on a bad day? He never threw any Tanks at me...
However, I did pre-order my copy of the actual game earlier today. I still think (and hope) that this'll be a great game with a lot of fun to offer.
Or at least be worth the $70 bucks I shelled out to reserve it. -sighs-