I mean to me I just don't get the same level of emotional responsiveness out of the Japanese language track. They speak loudly or softly, and in context I can tell if they're angry or not, but beyond that there's very little in the way of nuance to be picked up. The English language dubbers aren't simply mimicking the tone of the Japanese track, as if it were a rudimentary Jackie Chan dub, they're putting in real thoughtful performances themselves, and in many cases may be more talented than the original actors.
And while the Japanese language track may reflect Miyazaki's vision, it doesn't necessarily mean it has to be your favourite. He's directing people to read the same words, by and large, as the English language director... and they're both making judgments about what they believe sounds right. And while nobody would question Miyazaki's adeptness as an animator and storyteller, I've never heard the argument that he's also a superior caster and director of voice talent. To my ear, his voice actors sound every bit as Japanese (that is to say, typical) as any other anime I've watched. None of it is distinguishable. None of it is intelligible. I wouldn't know a good Japanese voice performance from a bad one.