I really like Org Mode, but I only need a tiny amount of its functionality. Emacs is my editor of choice anyway, so it's convenient to use Org Mode for my personal daily to-do list and backlog. And not even for a specific workflow system (e.g., GTD or whatever), just tasks with scheduled dates, deadlines, and some custom states. Agenda view is neat, too. That's plenty for me. It always impresses me though when I see how much others can do with it!