I think everybody has a different sense of organization, and the prevalence of organization schemes and apps is in hopes that enough people can relate to a particular app-developer's preferences and patterns. At the end of the day though, I think productivity is such a chaotic and fragmented genre of tools because everybody is different and there are as many productivity methods as there are people. I've certainly never found one that I've been comfortable depending on, and it just so happens that I've had the idea (and the skills) to create The Best Todo for years, details of which are lurking on some note pages in this pile over here (and a few over there).