Of the two, I've only seen Rookie Historian, which is my absolute least favorite Korean historical drama. I don't expect much historical accuracy at all from fusion sageuks, but there was honestly no point in setting this drama in the Joseon period. The characters behaved like they were living in the 21st century 90% of the time. Really the writer wanted to make a show about gender in the workplace and for some ridiculous reason thought Joseon would be the right setting. Absurd. I might be a bit more forgiving if historians and historiography weren't the subject of the show, but it seems rather hypocritical for the writer to have their characters going on about the truth and integrity of historical records when they have completely ignored said historical records.
I've already forgotten what the plot was about; it was some very generic, mediocre conspiracy plot. The romance was cute at the beginning, but just got annoying, because FL acts like a 21st century career woman who doesn't what to get married. Even if you don't get annoyed by the anachronistic behavior of the characters like I did, everything about this drama is pretty mediocre. The only merit of this drama is that viewers gain some awareness of Joseon historiography.
I will defend Shin Se Kyung and Cha Eun Woo a bit regarding Czakharina's comments. I don't like Shin Se Kyung much, and in some of her previous dramas I've had very negative impressions of her, but I do think Rookie Historian the best performance I've seen from her. Cha Eun Woo is not a particularly good actor, but he was quite charming. I wouldn't call his performance in this drama wooden (if anything he overdid some fo the facial expressions). Sure it's much more cute idol than charismatic prince, but its a pretty fluffy show, so I'd say his performance was passable. (I haven't seen him in anything else.)