Film grain is the only complaint with the video transfer. That's so minor, it disappears when the movie moves to the underground caverns. Clarity is remarkable, flawlessly capturing the perfectly set lighting essential to the film. Black levels stay consistent and deep to keep most of the frame concealed as intended. Even the bright reds stay together without revealing compression artifacts. The Descent needed a quality transfer like this to work on video. 
Dialogue is mixed low against the heavy action. At times, spoken words are indiscernible from the noise of the action. It's never particularly important, but there's little reason you should be forced to fiddle with the volume depending on the scene. Everything else sounds fantastic, from the bass to the eerie use of the sound field. The scares don't have the impact they should unless you can physically hear the attack coming from all angles. 
Two commentaries lead off the extras. Both feature the director in the lead. In one, he sits down with the cast as they discuss their experience and training for their roles. The next the crew explains the shoot and the script. Each provides a unique viewpoint on the film.
A complete documentary is the must view piece here. The Descent: Beneath the Scenes isn't just a clever title. This is a fully encompassing piece on the shoot, the plot, script, and special effects. It's crammed into a little over 41 minutes.
There's a short interview with the director that lasts seven minutes as he discusses the multiple endings he could have used (and did as the UK cut is different). Nine deleted scenes are mostly trims from completed scenes.
A surprising set of outtakes provides some great laughs. Rarely do you see bloopers from a serious movie, especially one as dark and grim as this. Storyboards, stills, and trailers finish the DVD.
If The Descent's keen eye for horror worked on you, Dog Soldiers is a must see. While nowhere near the budget, it's similar in its depiction of gore and practical special effects. Descent is the better film, though that is in no way a shot at Dog Soldiers.
Article comments
1 - Voice
well, i think this movie was one of the worst i have seen, in the end, that girl wakes up and ends like that. so all the action from the moment (she supposedly woke up) was never true, she was just dreaming, how gay is that