It was interesting to see this production so close to Barrie Kosky's Dialogues at Glyndebourne earlier in the summer. There as here the production can be defended on a textual basis (and there are some striking close readings) but the overall argument for me came at a cost of emotional engagement and dramatic tension.
Kosky's central thesis appears to be that the Earth (Erda) is being exploited and ruined by everybody else on stage. He thus makes the character of Erda much more present than would usually be the case. Almost the first image we see (before a note has been played) is a practically naked Erda walking very slowly across the stage. The most effective deployment occurs in Scene 3 when she, or more precisely her breasts, are hooked up to Alberich's mining machinery. Elsewhere I wasn't convinced having her hovering around in scenes, so far as I could judge from the Amphi largely ignored by everybody else, added a great deal. And I think it comes at a cost - sometimes this is just distracting (some of the wandering about as with other aspects of the movement), but it also for me reduced the impact of Erda's intervention in the final scene. I'm sure the intention is to heighten not diminish our concern for her, but I'm afraid for me it had rather the opposite effect.