[gglitch]

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.