I took a full week off for Thanksgiving/my birthday, and spent a good chunk of that time reading this 460,000+ word beast 
I am a dedicated fan of Brandon Sanderson, and this is my favorite series of his, for its huge emotional lows and highs, and the “Branvalanche” of big reveals and “oh shit” moments that set the story on fire. Of course if you don’t like epic fantasy this won’t work for you, since it takes a few hundred pages to set up all the pieces before knocking them down… but there’s a lot of character development and great humor and action in the process.
This book was, even more than any previous ones, really big on themes of mental health. People who have been struggling too long without rest, not acknowledging their own traumas, break. While there are literal physical battles in this part of the story, it’s now much more about battling one’s inner demons as well as contests of wit and cunning rather than the sword.
Most of Sanderson’s novels are connected through “the Cosmere” and those connections are showing much more now than ever before. This book wouldn’t make much sense without the previous three Stormlight Archive books, but there are also a ton of tidbits and little revelations which reference his other worlds. However, I don’t have an encylopedic enough mind to put all of those together and realize on my own that shadowy-figure-with-a-completely-different-name who figures distantly into one of the subplots is probably a (dead) major character from another world, and I still felt the impact of the story just fine.
At this point in the story there is some heavy magical research going on, and some of it even touches on sound theory. Phase cancellation becomes a deadly weapon, albeit in a way that calls for more suspension of disbelief than, say, magical flight, or people who cast shadows in the wrong direction 