As someone who dabbled a bit with it about two years ago:
It is extremely detailed. It goes to the level that you can manage the construction of new buildings by allocating the right ressources and machines to the construction site in the correct order. Of course you also have to plan your bus lines, train signal controls, electrical grid and so on in detail.
With that much detail it is also quite ressource hungry, so i had to stop as my towns started to lag at about 5.000 inhabitants.
Bonus points if you have some cultural connection to the eastern block. I recognized many things, from prefab buildings, over cars and trains even up to the lamp posts from my country.