I actually just tested this out with a snippet from Small Gods. It still sounds very robotic and, in my opinion, is nowhere near good enough for these books.

The timing between sentences and paragraphs is inconsistent, the intonation for sentences with ellipses is completely wrong, hyphenated sentences are treated as continuous strings, and it can’t get names of characters or places remotely close to their intended pronunciation.

It might be fine for reading a news article, but it is nowhere near ready to perform an audiobook.