I have to write this for my parents. They typically only watch Korean drama's, you know, a nice set 16 episodes and they're finished. After watching bits of this and the mini-series on Netflix, I talked them into trying it. They were unconvinced, thinking it was too long, but started anyway. They binged the whole thing within a week, were both sad that there was no more and hoping I could suggest something else.
The female lead is great, she's cunning but not unkind, and I loved the interactions between her and the emperor, the chemistry is great. It was nice to see a woman who didn't whine or scheme, where we weren't sure of how she'd get out of a bind until it happened. The politics between concubines was ruthless and the opening song will be recognisable for the rest of my life.