You wanna know why I hate movie-version Legolas?

[Galad Aglaron]

I didn't even mind her taking Glorfindel's job. I mean, he shows up once and vanishes, but give Arwen the job and you ensure that the audience remembers that Aragorn has a girlfriend and not forget her the second they leave Rivendell. And giving her the credit for Gandalf and Elrond's water-spell? Well, it's a little bit annoying, but it's more dramatic, at least.  

[Rudhe]

I suppose. Unfortunately doing that changes her character from the book. Suppose it can't be helped.

Poor Glorfindel always gets replaced.  

[Tears of the Siren]

I have to agree that it does change her character, but if they were going to replace Glorfindel anyways, I think she was the right choice. It introduces her in a memorable way and if Glorfindel had been used it would have left the audience wondering what happened to him.

Giving her credit for the water spell was also an artistic alteration I'm willing to forgive. Granted it makes her appear much more powerful than she is considering that is took both Elrond and Gandalf to cast it in the books. However, having them cast it would require more explanation so that those unfamiliar with the books would not be unduly confused.  

[Berzerker_prime]

At least they didn't have Legolas going way too far west on his way to Rivendell the way they did in the Bakshii movie. that was just ridiculous. If it was a choice between Legolas and Arwen, they made the right choice.

The water spell, however, irks me to no end because it gave Arwen, and by extension all elves, magical powers that they simply don't have. I would rather have preferred a short explanation that Elrond and Gandalf had used Narya and Vilya. I don't think that would have been overly complicated at all.

Berz.  

[Tears of the Siren]

Even in the books it wasn't completely explained how Elrond and Gandalf accomplished the water spell. Gandalf was never said to possess Vilya until the end of RotK when he was about to leave Middle Earth. I'll have to go back and check, but I don't remember Elrond being specifically mentioned as possessing Narya at that point either.