Decent enough overall. Nice to see Durzo again. But even knowing this was a novella, I felt shortchanged. I think I would've been less disappointed in the length if a full 20% of the eBook weren't an advertisement for the author's other books. 5%, great. 10%, I feel a little irritated. 20% of a book that's already short as-is? Downright disappointed.
On the other hand, maybe the device should only count the % of the actual story, not including the extras.