This is a well-written and well-acted series. It's nice when a show or movie does not have to depend on special effects and action to be good.
As others have mentioned, I just have trouble believing some of the casting. It's bad enough that most of the actors have English accents. Having more Russian actors, or at least actors that look and sound Russian would have been preferable.
The most unbelievable aspect of the casting is the number of actors of African descent. I have a hard time believing there were that many (if any) people of African origin in Moscow at that time, and I'm sure none that would hold a position like Minister of Culture. Very unbelievable. I know when I visited Russia (including Moscow) around the year 2000, the only African people I saw were young, male African exchange students going to a university, and I saw less in all my travels around Russian than I see in one episode of this TV series.