Unfortunately? Hopefully the dub is okay. I haven't had much problem with Disney's other dubs for Miyazaki's films. I've seen them in both languages and thought they did a fine job in either language.
Now you'll get to see Joseph Gordon-Levitt as Jiro. Given his acting pedigree, I would be shocked if he doesn't do a better job than Mr. Evangelion.
The dub gives us a Looper reunion of sorts as well because Emily Blunt is voicing Naoko. I'm not as confident about that bit of casting as the only voice work I've heard out of Emily was voicing Juliet in that Simpsons ep from a few years back that parodied Heavenly Creatures. And her delivery there certainly won't work for Naoko.