Started to watch the series cause I needed some dark themed action-filled crime drama cannot say that I did not get what I've wanted. I love stories about serial killers both fictive and real ones so I had expected that this series would fit me quite well and it did. The soundtrack could highten or lower the impact a series can give me and I was very satisfied with this OST, it matched the series well and I could listen to Son Seung Yeon's song on and on. One of the serial killers in this series particularly made me feel amazed (bank teller). The revenge plot only added to the series. Still I cannot say that this series became one of my favourites of all times simply because the story wasn't so exceptional and I would've loved to see more of the crime squad member's personal life not just the main character's. Detective JCM's character was missing its behind story, it felt like he was abandoned by the writer. It would have been great if det. Woo would've been a little more vicious at times after all he is supposed to be the "real bad cop". My favourite scene was the one when JHM fell and I expected him to die on impact but he seemed like he had supernatural powers and risen from the dead too many times. I can understand that his presence was much needed to continue with the plot but still enough is enough, he was like a damn phoenix and the shows effect of credibility suffered because of his repeated revivals.
I did not watch Luther nor I intend to do so so I could not compare the two series.