Flights between Prague and Vienna are ridiculously expensive. In addition to the flight fare one may also need to add train or taxi rides from the airports to the city. Even in the most opportunistic event travel time will exceed 4 hours.
The alternative are rides by train or bus. They are significantly cheaper and offer a lot more comfort. Trains leave and arrive at the respective main railway stations in the middle of both cities. Today, I am taking the ride from Hlavni Nadrazi Praha to Hauptbahnhof Wien. Since I bought last minute I opted for First Class since it was just 300 CZK more expensive than economy wagons. While booking the ride, there were differences in price between the desktop site and the mobile app of the Czech Railway. The desktop portal was cheaper for almost all searches and I paid around 1100 CZK for a one-way ticket while a economy seat would have been around 800.
It is a smooth and uneventful ride with just very few stops on the way. 4 hours is the complete travel time. RJ79 train is owned and operated by OBB, an Austrian state run railways. The wagons appear clean and in excellent condition.
On the bottom line it is a very comfortable train ride. It is possible to order drinks and food, one bottle of water is complimentary in First Class. Wifi is provided free of charge. Connection speed isn’t great, but should be sufficient for normal web apps imho. It’s less stress than riding a car and a bit less time consuming than both, travel by car and airplane. Observing Bohemian villages and Moravian landscapes enroute to the Austrian capital is infusing a mix of tranquility and providing ideas for future biking trips. The forests and hills along the way are peaceful and show nature from its best side. After RJ 79 arrives in Vienna it continues further south to Bruck an der Mur before it arrives in Graz, its final destination.