I've been using it for about 10 years in a somewhat modified and ever-evolving version. I spend about 15 min per day staying organized, plus maybe an extra 30

I've been using it for about 10 years in a somewhat modified and ever-evolving version. I spend about 15 min per day staying organized, plus maybe an extra 30 min once a week. Results? I've been told by co-workers at multiple workplaces that they're impressed with my organization and follow-through. I've seldom had a boss suggest that I'm focusing on the wrong priorities at a given moment. Mind like water? Maybe an exaggeration; but I'm able to handle about 10 times as many simultaneous responsibilities now than I was a decade ago, with less stress. Though flexible, GTD is an extremely extensive system that can require a pretty significant amount of overhead, and doesn't fit everyone's style or type of work perfectly. Personally I find it less helpful outside work, for instance. But it offers a lot of principles and techniques that you can adapt into a personalized system that works for you.