I liked Laputa, but it was nowhere in the same league. It betrays more 'old Miazaki.' Was it me, or were several of the pirate characters very Lupin-esque. Anyway, the story, animation, and conception weren't as good. That still made it better than a lot of things--it's still a Miazaki.
As for the about question, the movie has some typical Miazaki 'Man vs Nature' themes mixed in with a adventure-style plot. Two young teens (or younger? not sure) have to discover the secret about a mysterious flying city from the past. Kind of an Atlantis lost-technology stort of thing. There are some pirates, lots of airships, and the requisite mysterious strangers and pasts. In all, it's a bit more goofy than later Miazaki works, but not too bad.
As for the introduction, what a stupid thing to do! They knew that most of these DVD's would be bought by fans who wouldn't care what some guy from Pixar had to say. Who's inane idea was it to put those intros on, anyway?