I accidentally came across this drama & I am so glad I did. It was Ji Chang Wook's Healer look that attracted me to watch this one & this was his first work I have watched.
One thing that attracted me to this was the Arrow vibe this drama gave. (If someone has watched Arrow Season 1, then they will know what I am talking about, the vibe is similar in both).
This drama has everything- edgy thriller, exciting music, interesting characters, mind-blowing gripping plot, believable romance, suspense, action & comic relief. It's a package in short.
Story is great but I gave it 8.5 because I felt the ending rushed. I could have easily used 2-3 episodes more to give it a proper closure & cover all plot holes. I liked how the show wasn't draggy at any point. Somethings that could have added to make it the best-
1. A little more focus on backstory of the villains.
2. On 5 friends journey of being pirate reporters. This could have made the villains more layered.
4. MoonHo's relationship with his colleague & a little focus on his "First love thing".
5. Female lead's story along with her mother.
6. Childhood of the leads since it had some troubling things & Healer-Ajhumma arc.
7. Some other little inconsistencies- like the one with Moon Ho's minion who was working as a double agent.

Acting is great. Ji Cang Wook transforms smoothly from being sassy, bad-ass man to socially awkward, stammering BongSu while still showing glimpse of Healer in his behavior.
Park Min Young is cute, brave & beautiful. I loved how she breaks the mold of typical kdrama lead & is everything I love about female leads. She is brave, vulnerable, yet positive. I love her portrayal of PTSD & her way to deal with it by singing songs and dancing. She takes things at face value and is willing to show empathy & courage whenever it is needed. She chooses to show empathy for other instead of drowning herself in self-pity about her troubled past.
Moon Ho is one complex characters. He keeps you conflicted for a long time. He has a dark side but also a caring one. And the actor portrays him so brilliantly. His acting does half the job to reflect complexity of Moon Ho.
Ajhumma is brilliant. The fact that a middle-aged lady with superb hacking skills & knack for knitting is so good to see. The characters elevate half the story because they break the stereotypes of K-dramas.
Rest of the cast is just fluid in its acting be it teacher, Healer's minion, Jian's mother, Jian's adopted father. Even villains are great enough to literally make you hate them- be it creepy secretary, Moon-Shik (He isn't absolute villain throughout the show & I wanted to see more grey shaded in this villain), Boss.

I loved the music. Especially the suspense filled music. It creates the perfect environment to keep you in toes. Actions scenes are nicely shot & I officially became a fan of Chang Wook with his action scenes. The portrayal of romance is so nice. I liked for the fact that they didn't have any 2nd lead thing here even though there was a confusion about Moon Ho being second lead. The love story is believable from interest to curiosity to protective feeling to romance & did I mention the jealousy of BongSu with Moon Ho & his alter-ego & the also the chemistry which was evident from their first scene together (Wook's intensity of gazing, sly smiles and that handsome face, GOSH). Even though Jian falls for Healer, I loved how it's BongSu who fell for Jian first.

I can re-watch this show every once in a while just like I can watch Arrow Season 1-3 countless times. Such shows are rare & it's rating is definitely well-deserved.

I am willing to overlook the plot-holes because the good simply outweighs the flaws in this drama. If you want my recommendation for this show-
JUST WATCH IT ALREADY.
Show like this is rarely made & I will keeping an eye on Wook's work from now on.