Because of the mixed reviews, I was hesitant to watch this drama. In the end, I did watch it only because IU (Cindy) co-stars in it. In that regard, I may be biased : she was stunningly beautiful in every scene. The vulnerable-yet-strong persona suits her beautifully. If you are fans of IU and watch this drama, you probably won't be disappointed.

I liked The Producers, but I was left with the frustrating sentiment that it could have been so much better.
This is not, by any means, a bad drama. Both the writing and acting are sincere. The characters are flawed in very relatable ways, and the depiction of their interactions, aka the story, mostly steers clear of the heavy-handed tropes (unlikely coincidences, misunderstandings, unrealistic change of character,...) that tend to plague k-drama. The comedic moments were hit-and-miss, but most were light-handed enough, and some were hilarious enough, that I did indeed laugh out loud once in a while. Kim Soo Hyun (Baek Seung Chan) truly shone in that regard.

The first few episodes felt like a Korean take on The Office, and the newbie's confrontation with the "real", petty world of business felt, at least in a comedic sense, right: because his own reasons for joining this world were so childish and misguided, his ordeals were funny. I can't spoil the show, just let me say that this arc becomes far reaching (not as a character arc, more as the conceptual arc of making life-defining choices based on the ground of love) in a scenaristically brilliant turn of events.

What makes me sad about this drama is that, while it is always respectful of its audience, it did not commit to writing a meaningful resolution for its characters.. There were so many dots let to be connected.

My guess would be that the writer had the perfect drama in mind, but that, ironically, some producer ruined it.
Or, maybe, it was the writer's intention that so many likable characters should be left hanging. A slice of life...?