I watched this movie because I've read most of Deon Meyer's books. I'm glad I didn't pay to see it in cinema.
The movie is dark and has a lot of action, and the photography is alright. It tries to have a complicated plot about corruption.
Unfortunately in the movie the plot is mostly an excuse for a series of stunts, punch-ups and shoot-outs. The usual fare where henchmen take one or two punches but the main bad guy can take a hundred punches and keeps coming back.
Then I read the book. It shares the title, some characters and the main corruption theme but that's where it ends. All the nuance from the book is lost in the film in favour of quick and easy solutions. I won't go into spoilers but book and movie have different story arcs and a very different ending.
So if you're not interested in much of a plot but just want to see guys beating each other up, by all means, watch the movie.
If you want a more nuanced story with interesting characters and more realistic fights, read the book.