Bullet trains and high-speed railways are actually people's names for trains starting with D and g. in fact, both high-speed railways and bullet trains belong to multiple units, but the speed of the two is different, and the G train is relatively faster. Therefore, there is little difference in the comfort of second-class seats.
They are all the same models. If you must be more comfortable than anyone:
In terms of ticket prices, bullet trains are more comfortable and slightly cheaper than high-speed trains.
In terms of time, high-speed rail is more comfortable than bullet trains, and the same distance is faster.