> No problem if it's the book I want, but the preview is just not enough
Manning has a decent solution to this. You can browse the entire book, but only a small section of it at a time is “descrambled” in the live view.
On more than one occasion I’ve used this to look up some specific topic, which was immediately viewable (and unblocked me on that problem), then gone on to purchase the book because I know it’s high quality and I’m likely to refer to it in the future for other reasons.