This is one of those shows that you would find tons of conversation scene. Lots of talking but intensely fun. I believe not all people can savour a crime show without many actions.
Few things that i think can be improved.
1. I believe they can tell more about hwang si mok surgery. The backstory behind this fact is too shallow i think. Not enough information.
2. Kinda dragging a lot for a case to be solved. Sometimes too much airtime taken to debunked a mystery. But somehow this show manage to pull it through without me having to drop it off.
Few things that i really really liked.
1. The acting is superb. We have bae doona who is my fave. The main protagonist also carried it out really well. And also the villains really getting me on my nerves.
2. Not too much romantic scenes. Ive been longing to watch a kdrama without those romantic scenes as i prefer it that way and this show legit one of it. Subtle love scene makes this show feels tight and compact.

Conclusion: As i have stated, this show may not be everyone favourite. And i can see why. Lack action, lack romance you name it. But to me this show is awesome.