What most manuals on the web get wrong is not offering a single-page version, so you're forced to use clumsy search engines (on-site or third party) to search through the document. With manpages, the whole manual is usually in one document. Some big programs split it, usually for the worse.
Big time. I don't do that very often anymore, but it used to be how I read all documentation. There is a lot to be said for being able to flip through physical pages with a highlighter in hand.
