I really enjoyed this drama.
The plot is set up to be a palace/political thriller, which I like, but is really overdone--however, this show twists that plot by adding in a mystery that the Crown Prince and his people are trying to solve. The political drama blends into the overarching mystery nicely, which makes the plot fresher. There were some things in the plot (villain choices towards the end of the show) that I thought were a little silly, and parts of show dragged (too much screen time for unnecessary characters), but I could overlook all of that because I was enjoying myself so much.
Also, I love love both the Crown Prince and Min Jae Yi as individual characters, but I really loved them together. The drama really showed how they respected each other and worked well together as a team. Their romance is slow, but so lovely. It's all about the YEARNING.
I can see how this won't be for everyone, and that's okay. Everyone is entitled to their own opinion. However, I think that this drama took an overdone plot and gave it a fresh twist. Do I think some things could've done better or that more time could've been given to the interpersonal relationships between the characters? Sure. Does that lessen my enjoyment? No.
Overall, really loved this one.