I enjoyed watching this every single week but it was not without faults. I agree with the comments that it could have been cut down to 16 episodes. The first four episodes, as well as episodes eight-ten were my favorite in the whole series. Despite having more than enough time, the ending still felt rushed and poorly paced.

[spoiler] How the heck did Dam-i survive the poison?? [/spoiler]

What kept me watching each week was the really fantastic cast and their antics.

Eun-bi was stellar. She managed to pull off a cold, aloof King with an air of grace and charm. [spoiler] The scene in episode seven where she loses her cool and beats the sh*t out of the envoy from Ming, and then faces the real and emotional consequences was my favorite scene in the whole drama. [/spoiler]

Rowoon as Jung Ji-woon, was such a golden retriever boy, each scene with him falling for the "King" was so cute to watch.
I felt the most invested in the conflict between Ji-woon and his father (very skillfully acted by Bae Soo-bin), and was very satisfied with how that story played out.

I also was so impressed by the relatively new (at least to me) Nam Yoon-su as Lee Hyun. His dimples stole every scene he was in, and I can't wait to follow his next projects.

I do wish the drama had given more depth and understanding to Choi Byung-chan as Kim Ga-on. There was a bit of mystery of his character in the beginning that was very compelling, but they never effectively drew on him as a character and in the later half of the drama he was seemingly a glorified errand boy. And I don't even want to talk about the [spoiler] sheer ANNOYING plot point of alternative marriages to people you don't love and how underutilized and underdeveloped Noh Ha-kyung and Shin So-eun were. I had to roll my eyes anytime they were on screen and I know it was not the actresses fault but sloppy writing.[/spoiler]

I'd say this is a solid 7/10 for me.