This kdrama is well done. It is not focused on "big themes" but analyzes interpersonal relationships [like romance, friendship, family] and emotions [like jealousy, grudge]. Although it's a simple "office drama" it's well structured, the plot it's interesting.
Sure thing there are some clichés, I'm referring to Kang Tae-moo's grandfather or Jin Young-seo's father.
Furthermore the first meeting of the side couple [love at first sight], their quarrel over Young-seo's colleague and the initial 'situation-ship' of the main couple. However both couples are 'correctly' developed. I appreciated Kang Tae Moo's confession as soon as he realises his feelings, I think Shin Ha-Ri is really cool and strong, and for me both couples can be considered green.
The acting is marvelous, referring to all the members of the team, so natural and plausible. I have to say my favourite character is the main female lead, she's amusing, sunny, charismatic <3
The music was balanced between serious themes and funnier ones, so it perfectly represents the soul of the show.

Rewatch
I have to admit that I already watched the series few times after the first. It's so enjoyable.

p.s. I don't consider RW in my final rating