I don't post very often on this forum. In fact, I haven't posted in a very long time, but I wanted to say a few words concerning Sanderson's speed of writing versus GRRM.
While it is true Sanderson is publishing books at an astonishing rate, his Stormlight Archive series, his most popular series, is not progressing very fast. By the time the third book will be released, at least three years will have passed since the release of the second book. In between the first and the second, four years elapsed. Sure, this is still better than GRRM or Rothfuss, but it is still too long for early books in an Epic series. In a general manner, long delays between tomes typically happen through the middle section of a series or the near the end, when the author gets stuck in a hole... or falls prey to a too large and complex cast.
In between the two Stormlight Archive tomes, I believe Sanderson is publishing 5 books... That's great, but he is doing so many at once, I feel the quality has started to decline. I personally was not impressed with his later books. Mistborn also is, in my personal opinion, over-rated. It doesn't not deserve half the attention it is getting. His new Far West installment is a fun read, but it is not a masterpiece.