A very smooth ride, quick acceleration, and very quiet too. Minimalistic, clear automated announcements are very nice - but the system can't seem to give announcements about short platforms/selective door opening; guard had to do these manually. A lot of staff on board, not all of them know the layout of the train.

Some thoughts:
Despite looking looking lighter and smaller than the HSTs they'll replace, they don't feel cramped. In fact, carriages feel light and airy. Lots of legroom too.
Buuuuutttt: the chairs are far, far firmer. They might soften up through use, but they don't feel like they'll ever be as comfortable as on the old trains. The windows feel smaller (not as shorter and narrower) and a lot of chairs line up with the pillars - no window view.