All episodes watched. The plot twists were just out there (more than a few and each well portrayed from characters' point of view). As a novice to the story, I could never have seen them coming. 

The women were 'spectacular'. Each in their own way. You cannot simply call them crazy or power-driven like Yan Ze or Yan Han. Behind their choices lied attempts to preserve their or their offspring's lives, to avenge lost loved ones, to preserve the nation & not disturb the court, or in the Dowager's case, to accept and hope for the best. I found the Dowager most pitiful (quite surprised they didn't write her character as going insane or overwhelmed with grief). 

xiao lingling:

Who's Prince Jin's mother? I don't remember them mentioning it, or did I somehow skip it?

The drama never mentioned her directly. She would just be one of the consorts who happened to give birth to the first royal son (Prince Jin) before the Empress gave birth to her children.