I tried "The Wise Man's Fear" and the results were not so great[1]. It got a good number of the characters, but only showed them being related to Kvothe. Harry potter worked better'ish, but still not great[2].
My primary interest would be using these relational graphs to generate better structured summaries of stories in a structured JSON object for improved search/recommendations.
The thought of The Kingkiller Chronicle hasn't crossed my mind in many years, and now I have renewed sadness that the story will never be finished. :'(