I have been working with various forms of GTD for a number of years to varying degrees of success. I know that the reason it has not really taken is I have not practiced what has been recommended, though I have really tried. I have read the books and listened to all 8 CD's in Getting Things Done Fast.
I decided to pack it in and save for a work project list and forget about the @next action categories, waiting fors etc about two months ago.
How liberating it has been for me. How much more productive, too.
To those of you who are being effective and have a mind like water - my complements!
To those of you who have been struggling for a while - let it go - I am happier, less stressed, more productive. You might be too!