The first thing I would like to say it that it is totally worth the hype! I was wary about starting this show mainly because of how mainstream it was..but it was my first K-drama and I absolutely loved it. The plot was amazing how the writers brought all the genres together and also how the actors executed the whole thing.
Song Joong Ki's (Yoo Shi Jin) acting was really commendable especially since he is not like the character he potrayed, he is actually alot more mellow in real life (this is what I've gathered from various interviews and behind the scenes ). The chemistry between him and Song Hye Kyo was perfect (Well, duh, they got married in real life) also the supporting characters especially Kim Ji won totally rocked the sassy general role (omg I love her!)
Sound track was nice and made me check out the artists later, and Chen from exo did one of their songs which was a total bonus (All the EXO-L's put your hands in the air ;))
I highly recommend it to all the viewers wanting to watch a drama that is a perfect blend of emotions.
Seriously, you should watch it...
GO WATCH IT!! YOU WON"T REGRET IT!! :)