How well does it handle pronunciation, especially of things like proper nouns? This has been one of the harder parts I've found. On a financial web site I saw one example where the generated audio pronounced initiates as a noun instead of a verb. It's a subtle difference but can significantly change the meaning if worded wrong.

I was trying to use TTS to regenerate some old audiobooks and getting names pronounced correctly is pretty hard unless the model supports something like SSML.