For me, this drama was a really good thing to watch, and i strongly recommend it.
I really loved the way the stakes of the whole show changed through the episodes. It can be divided into two parts : the whole cross-dressing thing, and then the palace, and royal things. I admit that I was a little sad when Jang DongYoon let go of his character of "Lady Kim" but the way he pulled off the character of Nokdu made me forgot this sadness right away.
There are a lot of little funny details, like the famous "omo omo jinja ", which will be stuck in my head for years. But there are also really dramatic scenes, with heartbreaking lines from the characters.
I'm not saying that everything is perfect, some of the "plot twists" are somewhat easy to find. I don't know if it's because I watched a lot of Kdrama, or just I read to much, but both Nokdu and Dongju's real identities were kinda obvious for me. The one that really surprised me was YoolMu, he wasn't at all what I had expected for his character, and I really liked it, even though I came to hate the whole guy after all.
Overall, everything was well-balanced, and I really really like the end. It wasn't at all what was implied in the previous eps, and I really like it. It was kinda leggit, given the background of the characters, but I really enjoyed it. So far one of my favorite drama's ending.
A big plus for this drama was the whole cast. Jang DongYoon and Kim Sohyun are both part of my favorite K-actors, and they really rocked this drama. Hwang Inhyeop was a big surprise, I didn't expect him, but all his scenes were so perfect. Even though his character was supposed to be evil, I grew fond of him. But even the support actors were really great, and it was enjoyable to see every scene.
If I had a conclusion to made, I would this drama is really something to watch. Because it's a famous tale in South Korea, because of the cast, because of the action scenes, which are really beautiful and well-made, because of the OSTs, everything was good, and goes well together.