The acting for each character is terrific. As far as historical accuracy I've heard arguments on both sides. I think that if one was never that interested in the Monarchy -like me-it does give a general picture of the trials and tribulations the family. I did not know how terribly dysfunctional the family is and was. One thing that is loud and clear is how important-to a fault-the idea of tradition, and preservation of the Monarchy is. The Queen's power and refusal to allow those "in line" to follow their hearts is quite revealing. The strength of Thatcher in the face of a male dominated government and her refusal to back down to the Queen's wishes was impressive.
My across the street neighbor is a Brit from London and very knowledgeable of this stuff would fill in some answers to questions I had. Tradition and routine are always paramount.