I give this show 8.5 stars (rounded up to 9). While there are plenty of good period K-Dramas out there, this is the first one I've seen which focused so sharply on the misery and precariousness of life suffered by those in the royal family (as well as the general helplessness of life in the caste system). You truly feel the agony /suffocation of an existence forced to revolve around protecting the king, throne and/or preventing any appearance of treason, constantly having to sacrifice one's personal needs and dreams for the "greater good." It's also rare for a film in this genre to take such a psychological approach to its storytelling, or to see a villain who is so vicious and despicable, yet so tragic at the same time. Joo Sang Wook isn't my favorite actor, but he was perfect for this role, and he acted it masterfully.
All in all, despite being (mostly) a love story, don't be fooled: This show is 75% tragedy. However, if you can endure the torment, the great acting and (mostly) happy ending makes it worth watching (and yes, justice does eventually prevail).
ROMANCE RATING: * * * 8/10
YSY and JSY had very good chemistry together and shared 4+ kiss scenes, all of which (IMO) were deep, passionate and emotional (YSY especially comitted himself well). As a "pure love" type film, there was no real sexual tension to speak of, but there was so much else going on, you don't have much time to notice or care.
Recommended!