iPhone 12 mini; iOS 17.1.2.
I'm having issues with the new version of iBook:
randomly distributed extra blank pages throughout .epub's (but not with .pdf)
The rest are issues with iBook using Accessibility/Spoken Content.
reading stops at the extra blank pages mentioned above
reading stops at the beginning of new chapters
some, but not all, commas are said aloud during the reading
some apostrophe s are said as "ess" instead of as part of the word that precedes them, eg: the sun's up
apostrophe ll is said as "el el" instead of as part of the word that precedes them, eg: the sun'll get you
sometimes (consistently for where this happens) the first couple of words on a new page will be repeated. Not positive, but it might be with the ends of sentences that only have a couple of words left for the next page, or perhaps, dialog vs prose, eg: in (page a) "How much would (page b) I need?", 'I need' is repeated, so it sounds like "How much would I need I need?"
and perhaps the most frustrating: I'm using the Siri 1 voice, and almost once a day, when I start listening, it has switched to Siri 4, and Siri 1 needs to be re-installed in order to use it.
On a related note: When using AirDrop to move files from my Mac to my iPhone, I really miss the menu that allowed me to put the file where I wanted it (Books) without the need to download it to Files then share it to Books. I was truly disturbed that it came configured to send my private material directly onto iCloud storage, which was a pain to figure out how to store locally. It felt like an underhanded move to force me to use iCloud, and I didn't appreciate it. I found others online who felt the same way, and who struggled, like me, to figure out how to use local storage.
As an author, I use the Spoken Content as part of my editing, which is why I am so aware of these issue. More importantly, I want to ensure my blind/visually-restricted audience has access to my book in a listenable format. Initially, with the first problem (random blank pages), I thought there was something wrong with my book formatting, but then I took the time to listen to other .epubs in the iBook app, and found the same problem.
I hope this feedback helps you improve the Spoken Content, as well as the iBook app. I always cringe when a new major version of iOS comes out, because of the surprises and the multiple revisions it takes to get past the introduced bugs. I will end by saying the Siri 1 voice has come a long way from when I first began using it in 2020 with respect to it sounding more natural. And the ability to have my books read aloud for folks who can't afford expensive readers is priceless.