Here's my point: When you have actions scattered across context lists, how do you know if each project has a next action. That means you constantly have to keep making sure there is concordance between project and action lists. And updating this once a week isn't nearly enough in the environment I work in (journalism/film production).Waiting for is a next action. I am waiting for an event from someone else. I just review them on a weekly basis in case I need to do something else, like call and ask for the info or send and e-mail or something else to move the project on.
This is probably not a problem if you're in an electronic system, or if you have very few projects/actions.