Most people here pretty much echo my thoughts. Although, the truth is this is a very dense film that can be talked about for a long time, which bodes well for its ability to stand the test of time. People should still be talking about the film's meanings 20 years from now. I think the subject and lead character may be a little too niche to earn widespread love, but I think it will end up being one of Miyazaki's most respected films--in that, even if it didn't work for you, you'd respect what he tried to do here. As for the comparison to Porco Rosso, it's apt, but this is a far more personal and detailed film--and that detail is important because 90% of what makes this film unique is just how much time it devotes to the minutiae of its subject matter. It's much more niche and focused. Porco is still at heart a rollicking adventure, which makes it easier for mainstream audiences to love, but it's not necessarily a "better" film covering the same concerns. Just a different and more generalized presentation.

Two things I loved:

1. the film is SO geeky about mechanical engineering. A good 40% of the film is devoted to discussion about the nuts and bolts of airplane design--which makes the film so personal and self indulgent in a really endearing way. But it's not alienating--you might not get all the Xs and Os but you always know what the characters are ATTEMPTING to do in their designs.

2. Werner Herzog as a mysteriously wise German character in the dub. You can't miss his voice, it's so distinct. And Werner Herzog in an anime? AWESOME.