There are two things about my next action lists with which I've had to wrestle. After years of using to do lists, having them guide me in choosing next actions was no challenge. In fact, they're so comfortable, I would normally write impromptu to dos on the list before I did them just so I could cross them off. The hardest thing about next action lists for me, per the GTD methodology, was that they did not have due dates connected to them (which they did when I kept them on my Palm) and they did not have priorities.
The rationale is that a task either has to be done or it doesn't. If it has to be done, it doesn't matter if it's an "A", "B", or "C" task, it simply has to be done. David Allen also states that by relegating some tasks to a lower level, we perpetuate crises as we tend to work on the "A" (urgent) tasks while "B" & "C" tasks mature until the become "A's". This process can happen, and often does, overnight. We wake up one morning with a plate full of "A's" and wonder what happened.
The concept of no priorities is not new to GTD as this is also the advice of Kerry Gleeson in his book, The Personal Efficiency Program, where he cites the same rationale.
I thought it would be hard working without the priorities and deadlines, but I found that, due to my increased productivity, my tasks are being accomplished and are not falling by the wayside as I would have expected. In fact, I'm getting things done well before the due date that I would have assigned to the tasks. For next actions that must be done on a particular date or not at all, I use Allen's recommendation of either assigning a due date to it or placing it on a calendar page instead of a context list.
Who would have thought that an idea, such as eliminating priorities and deadlines, could yield an increase in productivity?