DRM, hands down. I understand why it exists, but it is a *huge* barrier to accessibility. Most epubs are 100% readable provided there isn't any weird formatting. Until recently, we couldn't even use our own screen-readers to read kindle books on Windows and Mac, which meant not having access to the text directly and thus, not being able to spell out words or see specific formatting or punctuation. This is now somewhat possible in the modern Kindle app, but only for specific books. Amazon takes baby steps toward full accessibility, so if you needed another reason not to use them exclusively, there it is. The good news is that it's getting better, and the Kindle app seems usable on iOS. People with slightly-more-than-basic computer skills can also use one of a few different options for stripping DRM from common book formats. Other than that, images with text in them are a bit of a pain since they have to be run through OCR. PDFs can often be formatted badly, especially if they have a duol-page layout. The good news is that you don't really even need to use text-to-speech to read a book and test it for accessibility. Just find a text converter, paste it into a plain-text editor like notepad, and make sure everything looks good and stays in the right order. If you can read it that way, we can read it. I specifically mention notepad because apps such as Microsoft Word support images, and notepad doesn't, so will completely strip out any text in them, which mimics what we hear.

This makes it sound like the situation is pretty terrible, but it isn't. I feel like I have fairly equal access to books, even if I have to look harder for them or do a few seconds of extra work to make them readable. It's 2017, and I no longer need to get frustrated because I can't find a book that my sighted friends are reading.

I've read some eBooks, I like to review them for a free copy, where the formatting split words, or where a word ended on one page and the sentence continued on the next.

Honestly, I think going through the first chapter of a book using text to speech should be enough for most people to be able to tell if words or paragraphs aren't displaying correctly, and with images, I've only "seen" the alt text in audio books, as I mostly read fiction.

I read a lot of ebooks, and use my screen reader to do so. I don't like using audiobooks, and braille takes up too much space.

What I like is that it's often possible to get ebooks the same way as everyone else and read them. I would like less DRM (especially the new Amazon KFX format) since I prefer to use my reader of choice rather than having to use, say, Kindle.

Generally speaking ebooks are well produced so the text corresponds to what it should be, though I remember an exception. It was a programming book but I can't remember now for what language, other than it was a functional language (maybe ocaml). Anyway, the book was an epub and it appeared empty to text-to-speech tools.

In sum: what I like is being able to use the same ebooks as anyone else. What I like less is the lack of standards and the difficulty using my own readers of choice due to DRM (epub for everything would be ideal).