I like this idea, because I don't trust ratings that much.... I'd rather see what my friends thought of the drama if they watched it, or at least the ones who have similar taste. Yeah, if I really want to know, I go to their lists to see if they've watched it, but it would save time this way.
(It's not like it takes forever to look through a few lists, though... but we're humans so we're naturally lazy I guess?!)