I've played with kGTD for a few days, and I don't think I like it. On the face of it, it seemed like a beautiful idea. Maintain your "horizontal" and "vertical" automatically. Unfortunately, it is that very ease that makes the system almost useless to me. I plan my projects, input them in the project screen, and then switch to the action lists. It seems to violate the "hard edges" principal that made GTD appealing to me in the first place. It seems that OOP should be used only for action lists. Project planning needs to be done elsewhere, probably on paper. OOP is very 1 dimensional, and project planning doesn't work in 1-D. It needs to occur in infinite dimesions -- something that makes the idea of brain mapping appealing. Sure, you can place the result here, but maybe the ease of the software is discouraging that kind of activity. Maybe it's just me.