I think my only concern about using a Wiki-based guide is the "anyone can edit" principle: when I've helped out with them in the past I've found I've spent far more time fixing up other people's edits than actually contributing anything worthwhile. And some people can get very militant about their miscorrections and/or very PoV edits.
I'm aware that some people take an entirely different point of view to myself and are of the opinion that any likelihood of useful information is worth sifting through all the detritus... but someone still has to do that sifting if it's not to become unreadable. Or maybe I just don't like other people much.
