Economic level: Pyongyang seems to have just finished fighting and is very poor; Seoul is developing rapidly and rich.
People's quality: basically ok.
Clean: Pyongyang is cleaner, South Korea is cleaner, much better than China.
Ancient buildings: There are many ancient buildings.
Modern architecture: The buildings in Pyongyang came from Japan, the Soviet Union and Eastern Europe, and were destroyed a lot; Modern architecture in Korea is more fashionable.