As a US resident I've become used to a particular approach to the subject of racism in policing, perhaps more closely hewing to stories originating in the states versus in the UK where this show is set.
The characters and their situations are more nuanced then many I see in crime dramas. After 4 episodes I am still not completely certain of the motivations of one(of the two) major characters. I suspect there is more beneath the surface then is readily apparent, but I'm not certain, and I'm enjoying the (potential) shades of gray as they surface.
The acting is impressive and the script well written.
In summation, if your looking for a formulaic approach each episode you will probably be disappointed. Stereotypical characters, ditto.
I could still be let down by where the show leads, in which case I will come back and modify my score and this associated review, but for now I'm enjoying the ride.