These are fascinating films, and it is great to have them widely available in this format. The prints are in very good shape, the scores for both films are excellent. The DVD transfers are admirable, and the extras are worth a look.
But ultimately what makes these DVDs worth owning are the films. Fascinating, entertaining, disturbing, and sure to repay multiple viewings.
Much has been made of the still dazzling special effects and huge sets, and that rather clunky but impressive dragon. Don't let that fool you. Die Nibelungen is a film about people, and it is to director Fritz Lang's considerable credit that the acting is across the board excellent, with Rudolph Klein-Rogge turning in an astonishing performance as Attila the Hun. Klein-Rogge's work is one of the highlights of silent film acting. He never goes too far, never over-emotes in that stereotypical "silent film acting" kind of way. His Attila is a fascinating lovesick warrior wanting to please his wife but still bound by traditions that he just can't break.
If you care at all about silent films, or films in general, you should buy this set. It is worth every penny.