The story is strong, acting was decent by the cast. Fight choreography is above average with some really good stunts.

Positive:
Interesting story with a STRONG start a solid 8 (but then it dropped)
FL is a strong FL that didn't turn stupid and weak mid way through like other dramas
Decent acting
Good supporting cast - I really liked the FL's guard, the tea house female & FL's double
Less than average # of overbearing characters with repetitive lines that you need to skip.
One on one fight scenes. These are rare when the actors can't pretend to fight at all but there were many enjoyable ones.

Not so Great:
NO chemistry between all 3 men with the FL. Chemistry with the FL = 0
FL wants to find the truth but always refuse to listen to other people for their side of the story, not very consistent w/ her smart character
She saves random people out of kindness yet she's not very nice to injured 2nd lead even after he took a knife for her. Again doesn't fit her character
Lagging after first 30 ep. lost direct after ep 40. Character twist didn't make a lot of sense
No humor relief, they tried w/ the little brother of the king's character but not much humor in this drama, not even subtle ones

This drama won't be like a Joy of life classic but the story had potential with enough mystery built in it initially. It wasn't just executed to the full potential.