Hello, Meg ...
Amongst Hayao Miyazaki and Studio Ghibli fans there seems to be those who prefer either what they call the "subs" or the "dubs." Personally, I have always preferred "subs" or subtitles. However, with this "Porco Rosso" film, the Disney dub with Michael Keaton is, in my opinion, excellent. And, preferrable to subtitles.
I have watched the trailers in Japanese (with subtitles) and I really do like the dubbed voices from Disney much better.
Since you already have the "sub' version, it will be interesting to read your opinion after you watch it.
This is my first (and only) Miyasaki film. I have not even seen "Spirited Away" which, as you know, won an Academy Award.
Looking forward to reading your "review."
All the best,
Richard