What stood out the most in this clip was the music. It's very ambient & low-key, but ominous at the same time. I almost always turn the music off in an FPS, but I may actually leave it on if the rest of the tracks fit well.
Also just want to say how great BitTorrent is...for me anyway. Big thanks to FileRush & I'm glad to see 3DGamers adopting its use, too.