Actually I waited till the end of the drama to watch it and I'm glad I did. From my experience of watching dramas I've got to say the past few years the cable networks of Korea are doing a better job at producing high quality stories that actually make sense rather than nonsensical romance stories only. From this sentence itself you can figure out that there's very little romance in this story.

First of all I shall tell my biggest complaint for this drama. That is that Sung Dong Il didn't get more screen time. His character was the most entertaining and obviously he's under the section main cast but compared to the other two he has little screentime.
Also another thing I don't understand how people say L's acting isn't memorable. After watching many, many, MANY dramas of his I've got to say his acting skills have improved 500X times. His character made more sense to me. The story is set in such a way that we don't completely fall for him cuz he sometimes is more tight assed. For me his character was refreshing. Another thins is I swear the female lead sometimes got on my nerves so much. Why can't she think before acting and after doing that and gets all sad.
Another fact was that I knew I saw him in some drama but wan't sure. Who am I talking about? L's best friend at work I mean. later I figured he was the king in the drama Faith with Lee Min Ho

Would I give this another rewatch value? Definitely yes