I am category C.
Why have I never subscribed? I've read the beginnings of nearly every article published (I get an email with the first part of them), and nearly never feel like I wish I could read the rest. Were the articles useful? I don't know - the blurbs you give for free often don't even tell you what the article is about. In reading other comments here, I suspect they aren't. I've read some of Roland's posts, and if his articles are of similar quality, the man simply shouldn't be advising ANYONE on how to umpire. Might as well ask dude and dumbdrum to write.
Besides ... I already get enough misinformation via my subscription to Referee magazine.