i find the dvda format can be either a disaster or completely brilliant, depending on the style of music. as an example, the dvda re-issue of nin's 'downward spiral' is freakin' brilliant and scary as hell. to hear this sort of bleep and blip and things coming from all different directions really works well for this kind of music. on the other hand, a friend of mine bought the alice in chains 'dirt' dvda and it's utter nonsense. having all of this compressed, dense, heavy music broken up and seperated really takes away from tha album and makes the production really, really awful.
as far as concert dvds go, i have a few. back to nin, the 'all that could have been' dvd is so good. and then there's a re-issue of 'ain't it dead yet' from a late '80's skinny puppy concert in winnepeg, manitoba. also really good stuff.