I have added a few more instances of errata over the past couple of days as I post more spells online (should hopefully have the last of the spells up this morning).
Overall, I think I have done very very well keeping down the number of errors in the book. On average, I think that Novus has fewer than most books, and that they are, on the whole, more minor than I have seen in many other books (including some I have worked on in the past).