Audible. The problem with Audible/audio books, at least for me, is when there are lots of characters in a book, it's harder to keep track of everyone and who is who. I do much better reading e-books or print books keeping all the different characters straight.
Mistborn has a huge number of characters in it, and listening to the books was a struggle for me because I was constantly stopping and asking myself who the author was talking about. Sanderson throws in 6 or 8 new characters at a time in places, and it's confusing until you get them straightened out.
Stormlight has a lot of characters, but they come into the book in a more measured fashion, so it's an easier listen in audio book format.