First - I love Wagner. Second - VIs are still young and virtual samplers (and most sample packages) are not fully matured.
My take (have not listened as fully as I might) is that in the first minutes the attacks on the instruments are too precise and the layers sound "sythy."
Now there are two ways to look at that problem. One is to work on getting this to replicate what a "real" orchestra would do.
That is to take advantage of those areas which sound otherworldly and "synthy" and design sound to the piece -- not assign "traditional instruments."