I'm really surprised I'm not seeing more low ratings. I watched the whole series, week by week, and every week left me wanting something "more". Quite frankly I was bored by this series. I didn't know who I should be rooting for or "why"; I didn't feel the characters, notably the ones who have an "emotional" romantic subplot, had THAT great of chemistry; and it just feels like the plot was very drawn out with little pay off in the end.
Ultimately I didn't feel a connection with the characters, and I didn't feel entertained. That's my personal experience with the show.
It's visually interesting but that didn't sustain my interest alone.
I will stick to historical K-dramas which I've had better experiences with.