On a whim I picked up the 28 Days Later blu-ray release. The original DVD release was pretty poorly done, especially in audio, so I was hoping for a redemption.
Video:
The video in this release will not impress. The movie was filmed on a purposefully poor quality camera to give the film an edge, and I wasn't really expecting too big of an upgrade in terms of video quality, but I did want something. It looks like an upscaled DVD, that's about it.
Audio:
This is where there is a huge improvement. The original DVD sounded flat, like a 128 mp3. This soundtrack is certainly better, with "the infected" screams being truly horrifying. Subwoofers will get a reasonable workout (they didn't go for the overdone bass booms like Saw or some of the new-age movies), but the gem in this movie is the screaming treble. It's what makes the tracks terrifying. It's what makes you jump. I think many of us are bass junkies at heart, but in a good horror movie, treble is what makes us move. I can't comment on the surround tracks because I'm a 2.1 guy.
If you are a Boyle fan, buy it. If you just want to enjoy 28 Days Later with better sound quality and a bit better video, give it a rent. It's worth that.
Cheers!