I could take either one of them. They both did a pretty good job. Of course I don't know why they had to out-continuity her in TVH, since she's been shown in the comic series' as being a great character. In DC's run she practically became part of the crew's family!
In regards to her being the traitor, I don't like Valeris. She's too one note, and almost sassily unemotional, if that even makes sense. I even think certain scenes would be better with Saavik in place of Valeris, like the scene in Spock's quarters. Just saying, if she had been the traitor, with proper reasoning, it could've been one hell of a twist.