I've just finished watching The Bird People in China and have skimmed the other reviews on IMDb. Like most of the others, I do enjoy Miike's work, though not to the level of unconditional love that seems to be common here. In my limited experience, around nine Miike films so far, none have been a waste of time and several are fairly amazing. Notably Audition, though definitely not for the faint of heart.
This film left me with mixed emotions. It truly has touching moments, but it also suffers from common issues with Miike films... disjointed structure, unmotivated action (particularly from the Yakuza character), a bit of excessive violence, a kitchen sink approach to ideas... every possibility explored, even when simple would have been more effective, and finally a liberal borrowing from other films. In fact I'm surprised this hasn't been mentioned in other reviews. Miike clearly took much of the premise and emotional content from the movie Local Hero. A corporate drone begrudgingly travels to a remote village and, to his amazement, is touched by the locals and the lifestyle. There's more to the similarities but I don't want to give away too much. Though I will note that he pays homage to his source material by throwing in a Scottish song as a major motif. I also didn't buy into the ending... it seemed to detract from the more realistic aspects of the film.
All of this aside, the film is worth seeing. The scenery is amazing and fairly unique, the photography handsome (considering the budget), Masahiro Motoki as Wada is quite good (as he was in Okuribito/Departures), many of the secondary characters are wonderfully drawn (another Miike specialty), it's genuine and funny at times, and it takes you on an unusual journey, an actual adventure... rarely a dull moment.