In Japan, there are two independently developed maglev trains. One is HSST by Japan Airlines and the other, which is more well-known, is SCMaglev by the Central Japan Railway Company.

The development of the latter started in 1969, and Miyazaki test track had regularly hit 517 km/h (321 mph) by 1979 but, after an accident that destroyed the train, a new design was decided upon. -- Wikipedia

I'd say Japan got into the technology quite early...

I rode the Shanghai airport maglev a couple of hours ago. I glanced up at the speed display a few times during the middle of the journey, and it was always within 290-301 km/h.

The journey time was something like 8 minutes, from the airport to Longyang Road.

You have to remember that the specs of the two trains are quite different, with the elevation above the track being much greater in the case of Japan (as a buffer against earthquakes).

The maglev to Shanghai airport is not a pleasant ride. Try the Shanghai-Hangzhou high speed rail. Not maglev but does 300 km/h and the ride is smooth as butter.

If I recall correctly, the Shanghai one topped out at around 478km/h... They actually run at that speed only a couple times per day.

431 km/h. I've ridden it, and it vibrates, for lack of a better word, disturbingly; you can really feel that it's pushing the envelope of what's possible. Not a big deal for a 7-minute ride, but would be a bit annoying to put up with for an hour.