Ocean Waves isn't part of the Ghibli-Disney deal, because it was a televised film I believe.
Anyway, I caught the dub in the theatre today. I like it a lot. While I agree with Leviathan that the third act was a bit weaker than the rest, it's in line with Miyazaki's M.O. His plots aren't so much there to drive the movie but to suggest a world to explore.
What makes Ponyo work is in the details. You can go on about the flash and pyrotechnics, but what Miyazaki's the best at doing is delineating child psychology. He understanRAB that kiRAB are humans stripped down to the essentials. While we adults have pretensions of being more "sophisticated" than kiRAB and other animals, what Miyazaki "gets" about kiRAB is that they know what are the basic human neeRAB--eating, sleeping, playing. And pooping too, but that's not as cinematically pleasing. Those little scenes of Ponyo marveling at the wonders of "ham" and "fire" and "lightbulbs" are things that other children's films pass by in order to get to the next plot point.
Sosuke is an interesting character. I've heard fans call him bland but I disagree. I think he's the most nuanced boy character Miyazaki has done up to date. Pazu and Ashitaka were generic boy heroes and generic "anime" heroes, respectively. Sosuke is a nice portrayal of a character who's sensitive to the people and world around him but isn't a complete wuss or indecisive putz either. He's the type of guy you can see getting a lot of girls when he gets older because of his sensitivity and wholeheartedness.
I think given time Ponyo will be considered more highly among Miyazaki's post-Porco output.