Some comments to add to Bruce's.
The setting is unusual in what is basically a traditional version. Instead of the forest, the first act backcloth is of towering cliffs which some found claustrophobic but I thought that was OK. The village is supposed to be remote,isolated, inbred - how else to explain the number of half-wits to be found there. The ruined Abbey in Act II worked well on the Hippodrome stage but it might be a problem on some on the smaller stages when touring.
I quite liked the animals but they were a distraction. Having come on and made quite an interesting effect, they should be taken off again pretty quickly. Perhaps the animals are to make up for the fact that the Duke's retinue is very sparsely populated. This becomes unfortunate at the end of the act when the nobility are supposed to be embarassed and disgusted by Albrecht. This passes for nothing if the nobility aren't there in reasonable numbers or, indeed, hardly there at all.
And, on the question of numbers, it is odd that the ratio of women to men in the village is about 5:1. No wonder Giselle is so quickly swept off her feet by Albrecht. Of course, one male in the village is Hilarion but, as so often and so mistakenly, his role seems pared to the bone.
The ending has been changed slightly. Giselle returns to the grave, a suitably horrible and well-staged effect, but then, because of her selfless love, she is forgiven her suicide and is taken up to heaven. It's a nice idea but the rising up to heaven didn't come over too clearly.
To sum up, I think there are some parts of this production which could be better and could be improved but it does keep faith with the underlying spirit of the piece and I think most people will enjoy it.
To turn to the dancing, I agree with Bruce about Muller and Murphy although I would want to add that Muller did the mad scene splendidly. Monica Zamora and Wolfgang Stollwitzer were also good at the preview. The corps were excellent both nights as were Nao Sakuma and Chi Cao in the peasant pas de deux.
A final comment: having watched from the stalls and from the circle, I would say that the ballet looks far better from the circle.