This drama started out slow but only got better. This isn't to say that I didn't enjoy the first episodes but that I found myself enjoying the episodes significantly more after around episode 6 or so.  So I encourage you to stick with it if you don't get all the hype at first.I'd never seen Lee Seung Gi in anything before and honestly I waited so long to watch this because I'm kind of shallow and was convinced he wasn't my type.  But like most dramas I put off watching, I can say that I'm mad at myself for doing so.  Why? Because Lee Seung Gi is great!  His character's evolvement from being immature and entitled to becoming a responsible, wise and deserving individual is touching to say the least.  Lee Jae Ha goes through so much and maintains his dignity and morals even through the toughest of battles.  Battles that would drive a lesser man to crumble only to never stand up again.  Ha Ji Won I wasn't as worried about, as I'd seen her in Secret Garden and all anyone ever has to say about her is good things.  She performed well as I expected.  Her character Kim Hang Ah is consistently strong and supports those around her with everything that she has.  The responsibilities she is given she embraces and even when those around her doubt her she remains calm and level headed.  But for me the real scene stealers would have to be Jo Jung Suk and Lee Yoon Ji as Eun Shi Kyung and Princess Lee Jae Shin respectively.  I'm sorry but Jo Jung Suk is just amazing and anytime he's on screen I literally can't even take my eyes off him.  He makes me feel for the character in such a deep way.  His character, Eun Shi Kyung, was honorable and self sacrificing.  He believed in those around him with all of his heart and his loyalty and willingness to do whatever it took to protect his king and nation had my heart rooting for him every scene he was in.  Lee Yoon Ji plays Princess Lee Jae Shin to perfection.  She portrays her pain and tortures very realistically.  I wouldn't have begrudged either of these characters more screen time, in fact I think I sometimes liked them more than the main couple.The story was well developed and the pacing was pretty consistently maintained throughout.  This drama does really well appealing to the emotions which I think is one of the most important parts of a kdrama.  I definitely balled more than once.  However, there was one particular writing choice that I would have to disagree with and if you watched it I'm sure you'll know what I'm talking about.  I don't honestly feel that it was necessary, and yes not every choice a writer makes has to be out of necessity but I really don't think it added anything.  It felt thrown in last minute and it didn't help me root for any particular character more than I already was so in that sense I would have to argue that the scene took away from the drama more than it added.  Also some of the English was pretty cringe but I can let that go.This drama's really good! And I wasn't expecting to enjoy it that much cause I'm not really into the military or political genres. So you should watch it!  It's worth your time.