I thought the performance was wooden too, but I'm hoping that's just part of the Clark Kent persona. I really don't like the Batman voice, but hopefully it changes when I see the movie.
I've only seen Watchmen and Man of Steel so I could be wrong, but from what I've seen, Zack Snyder doesn't seem like an actor's director. I don't know if he's directed dramas before, but I don't think it's his strength. Like Clown Prince said, if people are waiting for this film to get good reviews to get them to see it, I don't think they should bother. Although, I think people should read the reviews to see what the critic's problem is before dismissing a movie, or see what the critic liked before seeing a movie, because everyone has different tastes. I like the Dark Knight Rises, but I can understand why people say it's lousy because the plot, themes, and characterizations are a mess. There were just things I liked about that film that worked as a net positive for me (specifically, everything with Alfred and the atmosphere and dialogue in that first Bane fight). There's films out there that don't have many issues with the plot or characterizations, but I can't stand the dialogue or acting, so I can't enjoy the film. I'm not a film critic, so my judgement of whether something is a quality film doesn't really matter. Whether I can take something good from a film is what matters.
In any case, I'm glad for these trailers because I know what to expect. I'm expecting it's going to be like Watchmen where the scenes are going to feel stiff and the story isn't going to flow naturally, but it's going to have cool visuals and I'm just going to have to fill in the gaps for myself. If people aren't digging the trailers, I don't think they're going to like the movie. I really like the visuals, so I know I'm going to enjoy it.