I hate seeing voice actors. It ruins the purity of the character's image. That said, if I can again separate the VA's image from Karma's image, I agree that her original VA was quite good for her. The current one is inoffensive and does good work, but the original had a really solid grasp of Karma's tone, if you ask me. She was one of the better voices during that period of League.
I'd also like to add, though, that Riot's problem in those days wasn't always just not having great voice actors. I say she was one of the better voices during that period, but it's not like they didn't shell out money for Tara Platt. It's just, for some reason Tara Platt's Katarina feels rather uninspired. I'm not sure if it was the directing or the money. Karma, however, always had a soul to her voice, even when a lot of League champions were missing it for whatever reason. This is what I mean.