For a drama that had rating over 40% on average and over 50% for it's finale, I had a lot of anticipation for it. I feel that it didn't had much of a rollarcoaster plot but it played rather safe twirling around the factor of Yeon Woo's identity and a lot of the sharman part (which lengthen the drama else I don't see the fact how it could last so long).
I wasn't really into the pairing of Kim Soo Hyun (he's too cute! sorry fan girl mode) and Han Ga In (nothing against her) but she looked way older than him (hich she is in actual life and reflects so much on the drama), when Yeon Woo is supposed to be 2 years younger than Hwon (Hwon was 15 years old and Yeon Woo was 13 years old according to the earlier episodes when they were younger). It always look odd when the 2 of them are together, maybe it's because of Kim Soo Hyun baby face! I usually am a loyal shipper of the main characters but sadly not for this couple.
A few "could have been better" scenes. First, Prince Uisung's death. Queen Yoon (later in the show became Queen Dowager) and Yoon Dae Hyung have been worried about their plot to kill Prince Uisung being exposed. But there was no development from there on and King Sungjo barely mentioned it once when he found out that the Queen Dowager manipulated Princess Min Hwa to caused the "death" of the then Crown Princess Yeon Woo.
Second, Shaman Court Lady Ari's last words to protect the child. She was the crucial role who brought Shaman Court Lady Jang Nok Young into the "plot" yet she exited way too fast. I find that it didn't built up enough tension for the development of the drama.
All in all, it was an okay drama with good cast and okay story line. However, I feel that the ratings for this show was too overrated.