I know this is kind of an old topic but I just found the forum today and wanted to comment from a writer's perspective. (Web content is all I do.)

Yes, the quality will vary but you have to also remember that when someone writes for a free article directory they're doing so to promote their own site(s). Also, those types of articles are usually written very quickly, aren't typically referenced very well and tend to look a little amateurish--at least compared to a paid article.

That's not to say that free article directories are bad. You just get what you pay for.