There's something about Berlin that seems to inspire writers, and this particular series reminds me of another( probably better) police series called Babylon Berlin, although it was set in another era.
The magic of this series lies in the unique way that postwar Berlin is presented. It is a fascinating mix of ruins and decrepitude, shown in stark relief by the way some inhabitants live, particularly the Americans.
Having said that, there are many plots and sub plots the main one being the terrible crimes committed daily on the streets by all nationalities. There is a bit too much going on, so following all the different threads is probably helped by using sub titles.
The brutal nature of the series is I think helped by the engaging leading man. Several people have been critical of him, but I think a really tough guy actor would have turned a lot of people off. Elsie is an engaging character, and Max's brother is a great study in psychopathic behaviour.
It's not an easy watch, but it is an interesting one if you like to see how Berlin became the important city it is today, then this series can only enhance that experience.