I've been working on fully implementing the GTD systems for nearly a year. There a certain aspects that have definately helped my life, the collection and processing of ideas have been incredible, and I can't begin to explain how much more organized things are now that I have a filing system. But in the past year I've gone from a PC/PPC system, to paper, to Hipster PDA, back to PC/PPC, and back to paper, but haven't been able to tie everything together in a way that I felt was truly improving my productivity. I've come to the conclusion that my problem was related to implementing the NA's.
I work as a product director for a software company. My job consists primarily of talking on the phone, sending emails, going to meetings, and mocking things up in Excel, VB or SmartDraw. So let's say I have projects A, B, and C, each of which I have to make 3 phone calls, send 2 emails, and do 2 things in Excel for. With the NA's I cluster all my phone calls together, all my emails, and all my Excel work and bang through them. The reality is that my phone is a foot a way from my computer and all the programs I need to use are on my PC. To have NA context's for @Outlook, @Excel, @VB, @Calls seems like overkill to me since everything I need is within arms reach already.
The bigger problem for me is what I call topic-switching. If I make 3 calls about each project, then send 3 emails about them, then do 3 things in Excel related to them I"m constantly switching gears. I'm only working on the projects superficially, I know that thats part of the point of GTD but I find its not really increasing my productivity on the projects. I've found that by working on Project A, making the call, sending the email, working in Excel, that I"ve completely immersed myself in the project and new ideas occur to me more frequently that I capture and evaluate later. Then I going through projects B & C and do the same thing.
Maybe its not so much case of not using the NA's, but of how I process through them that has made the difference for me. I know what the actions that are needed to complete the task, I just don't cluster them together in terms of context. I process them more in terms of the project itself. So instead of saying I'm going to take 1 hour to answer all my calls, I'll say I'm going to take that hour and work on project A. Its definately relieved the stress in my work.
So now I'm down this, a good old Day Runner planner with a calender for my hard landscape, a tab for 'Work', 'Home', 'Calls', 'Projects', and 'Misc' -shopping lists, ticker items, Someday/Maybes, etc. I run ListPro on my PC with all the projects and all the sub items for them both long term and short term. I take the one's I'm currently working on put the in the planner under projects and the put the items that need to be done for them as a 'ToDo list' (ugh!) under work, calls, or in the calender. Then I allocate some time and work through all the items for the project regardless of their context.
I know this might seem like heresy but its working for me. I keep coming back to the old quote, 'The enemy of a good plan is the dream of a perfect plan.'