Well, Kristen Stewart is at the center of it all; so, I'll start there.
It took Robert Pattinson's performance in Good Time for me to stop scoffing at him for the Twilight movies and accept him as a damn good actor. Spencer is that movie for me with Kristen Stewart. She knocked it out of the fucking park. She's currently my favorite for best actress at the Oscars and I'm not foreseeing viable competition.
The movie is introduced as a fable of a true tragedy, which seems perfect. The film explores three days, from Christmas Eve to Boxing Day, through the eyes of Princess Diana and her interactions with the Royal Family, the help, and the press.
In some way I can see how people may scoff at the premise, especially nowadays. Yes, you're exploring the mental anxiety and turmoil of a beautiful woman who was born into wealth, married into greater wealth, will never have to worry about money, had thousands of dollars worth of clothing thrown on her every day at no monetary cost to her, had gourmet meals ready any time she wants it - it's a perfect life. Only, it's not because she loses all personal autonomy. She has no liberty. She gets scolded if she changes her clothing and leaves the blinds open. She has her wardrobe picked out for her for each meal, each gathering, each appearance. She can't grab a midnight snack without somebody hovering over her. She, as is said in the movie, needs to split herself into two people.
The film is written elegantly and in a vernacular which I found to be immersive. The direction is precise, fluid, and bears enough humility that you're not looking at how clever the director is. It's the anti Joe Wright of directing.
I do have to rant about the cinematography. Claire Mathon's work is next to perfect. I'm not saying that it's always the most gorgeous movie to look at; but, there were some scenes that weren't supposed to be gorgeous and she knew that.
This was also shot on 16mm film, which should be way more common these days. The first time I shot Kodak Vision 3 film back in college, my jaw dropped. 16mm looks like the 35mm that I grew up watching. It looks like a real damn movie.
This is my new frontrunner for Best Picture. I loved it. Go see it.