Within the cosmere universe, there is a one off novella that Sanderson wrote called "The Emperor's Soul". It is quite good, and it won a Hugo award.

I very much disagree about his worlds lacking authenticity. It seems you have some strange suspension of disbelief resulting from Shallan's dialogue (which I find is true to her character and upbringing). I agree some of the writing for dialogue is "off", but I feel much of this results from Sanderson's pace of writing.