I got the DVD as a gift and I noticed that the feature documentary on The Dark Side Of The Moon is followed by a DVD-only extra section. This section adds extra footage that was taped but not included in the documentary (probably to avoid making the documentary too long) - an in-depth part on Gilmour's use of the double and triple-tracked guitars, an interview on the nature of Rock 'n Roll with Roger Waters, a story on the background voices, etcetera.
For any fan on Pink Floyd or student of modern music, this DVD is a must-see. Especially noteworthy is the in-depth look at recording and producing Dark Side; since this was pre-computer technology, the stories about the tape-loops to sync the clocks for the intro of Time, the story by Waters on making the cash register sound for Money, using sequencers for the space sounds... Their creativity is astounding.
A few small details were so incredibly interesting - Rick Wright using a piano chord from Miles Davis' Kind of Blue for instance was a revelation for me, as I recognised the chord but couldn't place it.