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.