I will be traveling from Prague to Vienna in September. There seems to be several train options and I am interested in others experiences.
Have you already consulted the Man in Seat 61 site?
Description here for the 2 different train operators on this route.
https://www.seat61.com/trains-and-routes/prague-vienna-railjet-train.htm
Regiojet is the new kid on the block.
It is a rather flat ride a!omg a river delta--very flat. It is uneventful and a somewhat slow trip.
We did that trip in the reverse in May. The train was not crowded as we left Vienna but became very crowded further along. I would definitely recommend making a reservation for that trip.
David, are you describing Prague to Vienna journey? I did it many times. There is no flat river delta, more than half of way is hilly, gorges, tunnels, not like Switzerland but scenery is quite OK. While the train is not as fast as in France or Germany I would not call it slow either. 160 km/h = 100 miles per hour. And I appreciate that the ride is uneventful. Rather uneventful than derail like we had here south of Seattle few weeks ago.