If you were living in a place in China where you could just show up and catch a high speed train, you were very lucky!
My experience living in China is that for high speed rail departing from tier one and tier two cities, you would often need to book a ticket a day in advance, or - if you were winging it - be willing to go to somewhere other than your intended destination. And foreigners cannot get their tickets through the machine like people with Chinese ID card can, so that means waiting 30-45 minutes in the line to get your ticket (even if you booked online), before you even go through security, which is another 15-20 minutes. And if you show up at the main concourse 5 minutes before the train leaves, you will be denied access to the platform due to the airport-like boarding procedure. As such, I always had to calculate arriving at the dedicated high speed train station (usually itself 30+ minutes bus or subway ride out of the center of town) with at least an hour to spare.
It is still far less hassle than taking a flight, but it's not comparable to the real spontaneous opportunities of going by bus/coach or slow train (hard seat). With those forms of travel you really can just show up at a nearby station and go wherever, with little to no pre-planning and less stressful security checks. But then it will take hours to go halfway across the province. Of course, for many Chinese, that is the standard mode of travel, because high speed rail is still fairly expensive by comparison.
All that said... Pretty much everything about traveling by rail in China is better than it is in America. But traveling by rail in Europe is the gold standard, I think. Being able to buy tickets from a machine, not show photo ID anywhere (in the Schengen area at least), just step on and step off, that's real freedom of movement.