Of course I'm biased, but I think the new 5.1 channel surround sound mix on the Blu-ray disc included in Pink Floyd's The Division Bell 20th Anniversary Deluxe Box Set is fantastic.
It does not seem to have anything that was not previously in the stereo mix (unlike for example the 1975 quadraphonic mix of Wish You Were Here -- included likewise on a Blu-ray in the WYWH Immersion box set -- which made use of outtake tracks of guitars, keyboards, vocals, and even female backing vocals to help populate the additional channels), but you might hear some things you didn't notice before due to the inherent nature of 5.1 allowing them more space instead of being buried in the stereo mix. But in a few instances, things have been given a deliberate increased presence in the 5.1 mix. My favorite example is Marooned, which boosts the level of the piano, transforming it into a duet between David Gilmour's guitar on the right side of the room and Richard Wright's piano on the left. The left/right opposition was already in the stereo mix, but the piano part was less prominent compared to the guitar. The change seems appropriate since Richard Wright was co-writer of the Grammy award-winning instrumental.
