Never had a flight delay in all the years flying in/out of Narita. They have pretty a pretty good record of being on-time with flights in Asia. United Airlines is shit, though. Lost my bags this summer and when I got up to the counter to ask them about it and realized the other 25 people in line or waiting by the counter were on my flight, it became a given.
I got a bunch of miles on United all of a sudden though, so I'm gonna use them up for a cheap jaunt to Hong Kong or something, and then get back to collecting JAL miles.