Huh, I didn't buy the books because people were saying that the translations were horrible. I remember reading a post that compared the fan translation to YenPress' release. I can't seem to find the particular post, but I do have a screenshot saved:
I guess I shouldn't judge the entire translation just based on that alone, but YP messed up pretty bad there. If the rest of the novel isn't as butchered as that, I might pick it up and give it a shot when I drop by the bookstore to get the sweet Overlord hardcover release next week.