I wish people were more liberal with the Very Low Quality flag, at least on StackOverflow. SO gets enough questions that it can afford to throw out more, and would be a better site for it.
While most people seem to think it's only for things that can't possibly be salvaged in any way, I think we'd be better off treating it as "not worth spending the time to fix". Some posts, even after being edited to be coherent, still wouldn't be anything special.
I recently read something that said managers should spent something like 80% of their time with their best employees--making sure they have what they need and keeping them happy-- and very little with their worst ones (hopefully someone will be able to find a link). I think the same concept should be applied to people's posts. Let people use flags for the awful stuff (which is quick), delete it and be done with it. We should be encouraging people to spend their time not on making bad posts tolerable, but on making good posts great, which I think is a much bigger net gain for the site.
In addition to the formal description, Jeff has given some other advice on use of the Very Low Quality flag:
To me these cast a somewhat wider net than requiring that something be totally unsalvageable, though judging by another of his posts Jeff still favors a very narrow interpretation.
So I guess I'd like to flag more than Jeff wants (and I've backed off on flagging borderline cases). I just don't see why people should be so attached to low quality posts that will almost certainly be replaced very quickly.
I also think it'd be nice to flag bad answers when the question has good answers that cover the same points, but I'm still in the testing phase to see if there are any moderators that agree with me.