I think in general, how much you liked this production depended on how much you were familiar with the show and original/prior productions. I mean, for all the flaws I thought there were, if you went into this never having heard or known anything from WSS (okay, that's pretty rare), I'm sure you would have been blown away by the music alone. And I certainly don't fault anyone who felt that way.
"That said, I really doubt the majority of the audience noticed anything wrong with Karen's dancing"
I don't know, one of the worst aspects of it, for me, was that Graziella was clearly the better dancer, and since the Mambo is essentially a battle, the white girl "won" the mambo. That's just wrong. It seemed very obvious to me that Graziella was the better dancer and drew your attention, so I guess I would think some people noticed that, but hey, I could very much be wrong. But still, it was really bothersome. The white girl should not win the latin dance.
"Does anyone know specifically if Arthur made any cuts or changes to the book in the revival?"
YES! He took out Velma's stupid "ooblioo" line, that made me very happy.
And I think the Tony/Riff dialogue before Something's Coming was different, because I distinctly remember there wasn't an "uncle" and feeling that their friendship wasn't quite as established.
Then there was the fact that the lines were the same, but the direction just killed it, like when Maria's screaming KILLER! KILLER! at Tony, usually she just punches him and then collapses into him; in the revival, she just screamed it and ran into his arms. WTF?
And since lord knows I can't say this enough, let me explain why cutting the nightmare completely ruined the ballet. So both productions kept everything through the "Somewhere" song and through the post-"There's a place for us" repetition. So far we've seen Tony and Maria desperate to escape all the hatred, to find a place to be together, and at this point, they accomplish it, and they're happy. But then the music and the hatred are supposed to even come into their dream escape, the music sooo brilliantly changing from the dream to the nightmare, Riff and Bernardo coming back and killing each other and Tony and Maria not being able to stop it, and forced to be separated. Then they're back to the bedroom in desperation, clinging to each other, hanging on to a very small little hope. There's of course foreshadowing, and I think even they know at that point that while they'll try to escape, everything will get in the way, like it did in their dream. So in their desperation and fear, they make love.
Now let's take out the nightmare. So far we've seen Tony and Maria desperate to escape all the hatred, to find a place to be together, and at this point, they accomplish it, and they're happy. Then we go back to the bedroom and they reaffirm there's a place for them, and they'll be okay, and despite the fact that he killed her brother, they make love?? It makes sense that they do it because of the desperation and fear the nightmare brought on, but without the nightmare? That's just stupid and selfish.
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli