I made sure to view "Ponyo" before it reached the US. A July '08 film in Japan, it reached the States in Aug '09. I even watched it on a 15" monitor, and that bites. Why did U see it like that? In two words: Japanese language.
Every Hayao Miyazaki pic to see an American theatrical release was altered by Disney to bear an English-speaking cast. Discussing "Ponyo" yet again feels unsatisfying, and I'm sorry if it's repetitive. But it highlights my points perfectly...
I love watching foreign films and enjoy reading subtitles. I find it natural, seldom distracting. And, especially for movies that are "less than great," I think the original language and audio make a big difference. If it's not a great work, that extra bit of nuance may help it receive a fair judgment from the viewer.
A decent film can stand as a decent film when you get the added context of subtitles, language differences, and the like. They don't need any changes, nor do great foreign films. Odd Russian, Indian, or Italian sayings are much easier to take when you hear someone say it and then read it on the screen; you know it's something foreign, so you accept it.
Have you ever made fun of badly-dubbed Kung Fu films? Hearing "I will kill you with 'falling crane loves the lotus!'" sounds better in Mandarin than it does in English. Oftentimes, when a flawed-but-decent movie gets dubbed, those little flaws seem much worse. And now you have senseless lines and mismatched lip movement to add to the list of problems.
Also, remember that some films don't keep sound effects and voices on different audio tracks. When actors are over-dubbed, the sounds of action on the screen might drop out or sound wrong. Imagine, if you will: A Spanish man endangered by a Barcelona arsonist talks - and, somehow, English words come out of your speakers with no traces of burning, crackling destruction. Over 1 & 1/2 hours, that can have a big effect on filmgoers.
Worse still, a lot of dub work just isn't as good as the original effort. Even if the translation is done thoughtfully, the English voice-actors never speak to the director (Kubrick and some others excepted). They may just be reading the words straight off the page, with little preparation or understanding of motivation or the scene's content. All of my own "acting" is amateur, improvised, and used in my life - yet I know that effective acting relies on understanding what's going on.
Quick example of deadly dubbing: A friend got me to watch the anime called "Inuyasha" on Adult Swim. Every line was torture. In Japanese, it has the flaws of most shows, but it's a thrilling and emotional story, well-acted, with great roles. I almost mock fans of the English version - the players sound so bored! Bored whether they're falling in love, fighting, or dying. And the badly-pronounced foreign names...
To put it all in perspective, I will admit: I love "Howl's Moving Castle," and I've only seen the film in English. I caught it on STARZ (I had cable), and I ate it up. In particular, Disney did a great job in hiring the uber-talented Christian Bale to do the male lead. Then again, "Howl's" was already a good film, from score to characterization. Lovely, inventive, and fun.
On the flipside, I saw Jackie Chan's amazing "Project A2" on G4, dubbed - and was in mild discomfort the whole time. All the wonder and joy of a filmmaker's great work was drained as I had to deal with those incongruous voices. It really didn't help that Jackie Chan does his own dubbing, and doesn't handle English well. I won't be harsh, because Jackie's great and my Chinese (a very tough language) is non-existent. But an English "Project A2" didn't work; I turned it off.
This is also the reason that I don't own a copy of "Drunken Master 2." It's one of the best action films ever, and I've loved it since the HK Film Festival brought it to NYC. I just can't abide what Disney did to it - changing the soundtrack, altering the ending, putting in weird voices instead of nice subtitles.
If Ponyo had been a good/great film, I'd've seen it in the theater. Gladly. And I'd probably rent it later and watch it once in Japanese too. The English dialog would only have left me more disappointed.
In closing, I've seen most every pre-"Ponyo" Miyazaki film, and I always make sure to have the language set to "Original." Or, as I like to think of it, "Coke Classic." The quality of the story is always more important than what language it's in. I don't want to be spoon-fed any further, not when someone's already imagined a whole set of pictures and sounds for me.
Be warned, I have a good reason for taking a few minutes to share these thoughts: my next review will end up being as long as an essay (Bergman, anyone?). I try to be a little entertaining and a little thoughtful when I know I've got a mountain of words coming up...