You always have to decide. Say you are in the context "at office" and have a list with twenty action items on a list called @office. Which one will you do? You have to choose. Based upon your energy level, time available, etc.
David Allen (DA) outlines a process where you sit down (way before you start implementing a project), brainstorm / think through / clarify / define the endgame, and finally come up with "atomic" action items for that project. This is a fantastic advice.
Then these items are kept in various lists (that represent contexts; for instance "tasks I can do while I am at a phone" or "tasks I can do while I am at a computer / online / doing errands / ...".
Now you have a bunch of unrelated items distributed horizontally across various lists. As if "talk to my boss" [on the list: at agendas] or "draft the architecture for the platform" [on the list: at computer] is as important as "talk to neighbour re his barking dog at night" [on the list: at agendas] - And since DA recommends not to organise lists by priority you always have to review your lists to choose an action item. That means you'll have super important items buried in lists with trivial action items.
My issue with GTD is that it wants us to capture everything. Why does it want that? For inner peace! - DA thinks that whatever is nagging on me (internally or externally) needs to be captured / clarified / put on a list (to be dealt with asap or someday/maybe). As if my resources are unlimited. Why not take a decision way before and learn to clear things in advance, internally or externally (by saying the magic word: "no"), decide, that I don't want to follow up on that thing. Instead of having various lists with endless "open loops" that I want to close asap / someday/maybe. And by doing that, loosing focus.
I believe (like Peter Drucker in his book "The Effective Executive") that in order to accomplish anything of significance we need to focus our resources, "close the door", block as many hours as possible to work single mindedly on very few tasks. This is not what GTD says. It wants us to tackle everything that lands on my lists (sooner or later). And that is an illusion, that we can do a myriad of things and get significant results in our lives.
