To clarify: voice acting is only during cut scenes with special characters. For instance Yda & Papalymo. I went into the game expecting voice acting for all main missions. That is not so.
That being said, the voice over I've witnessed so far is superb. I'm not disappointed. You still get the chat bubbles in addition to the voice over. You even can cut short the spoken sentences if you're too trigger happy. Excitedly I've done this a few times.