New Led Zeppelin

Tweakgeek-the Earls stuff footage is great as is the Knebworth stuff-I think they've cherry picked performances from the later stuff to ensure there isn't anything substandard-performance wise.
Plant has a habit of being a bit critical-he's not a big fan of Knebworth either..................

I can't over how amazing the DVD sounds, even the material from 1970. Terrific recording...the band is in tune and Plant is right on key the whole time. Does anyone know if anything was overdubbed to "help" the original recordings. Whatever magic was performed was expertly done.

Tvad-my understanding is no although sometimes the audio and film were sourced differently from the same performance.
The version of Immigrant Song on the second disc from Australia is the only performance were seperate film (Ausralia) and music (America) have been spliced from completely different sources which would explain the jerky frame effect used as obviously it would be impossible to match them.
Of course it wouldn't be hard to imagine the odd overdub to smooth the thing out.
I think what maybe disproves this to a large extent is how selective they've been on editing the actual gigs.
Earl's Court and Knebworth filming must amount to at least 6 to 7 hours of material-on the disc itself it's edited down to (guessing now) about 2.5 hours.
I think there were probably ropey performances in there which simply didn't make the disc.................

I take it the DVD is multi 5.1?

Both 5.1 and stereo-as stated above.