I plan to play it in English. For me it's a no brainer. While I respect the difference in opinions of the pro-Japanese audio group, I can't fathom listening to something I can't understand even if there is English sub titles available. I know a few posters here prefer the original audio, claiming that the English voices suck, but to me listening to a foreign language is quite annoying.
I'd rather turn the volume off than listen to something I can't understand. There's only been one game in the last 30 years that I could not play because of a voice. Even without the volume on, I could hear the voice in my head. (Well actually to be fair there were more factors to it than just the voice. The character in question was personality challenged and I didn't care for the combat either.)