I’ve never been to Prague, but did visit Bratislava when it was still under Communist rule. It seemed pretty drab then—no doubt much better now. I got into a conversation with an Austrian woman who was also there as a tourist—she said it reminded her of the Soviet occupation zone in Vienna (before 1955)—nobody fixed anything.
Most people visit Bratislava as a day-trip from Vienna, as it’s only an hour away, IIRC Vienna-Bratislava are the two closest capital cities in the world.
Ditto with what was East Germany.
The Soviets left Vienna, because they signed an agreement that Austria was to never join NATO.