I'm puzzled by this. I'm reading /Introducing Elixir, 2nd Edition/ online right now in Firefox on a Mac, and it looks fantastic. Beautifully formatted.
I've just checked this book on Safari — it seems it indeed doesn't have the issues I've experienced while reading on Safari, like spacing between the letters in a word, tons of whitespace in weird places and poor image quality.
That means that overall quality of books ranges on the platform.
May I ask you, would you still prefer a Safari version of this book over, say, a PDF?
Tough call. I'm not at all unsympathetic to the variety of very good reasons why someone would prefer a pile of DRM-free files they own and can do with what they please. In this case, for me, it doesn't matter much; I have a Kindle on which I'd never try to read a technical book, so whether I read a pdf in Preview or a website in Firefox I'm kind of indifferent to. All else being equal, it seems to me that the web offers much more flexibility in design than a pdf, which must, at the end of the day, have standardized "pages," that don't necessarily correspond well semantically to the content.
That means that overall quality of books ranges on the platform.
May I ask you, would you still prefer a Safari version of this book over, say, a PDF?