If you are someone who has or intends to read all/most of the Cosmere books, then the maps of each solar system and run down of the planets and dynamics within in it (provided by a character who makes a cameo in a number of the various series) will be something you'll love. No longer does the Cosmere feel like this murky place with too many lands I am unclear about. 
 The Secret History of Mistborn and Edgedancer are probably the two more relevant stories as far as containing information and events one would be well off knowing before future books come out. 
 The others are of varying quality but all quite good. I especially liked The Emperor's Soul and Shadows for Silence in the Forests of Hell.