Autofocus time management system

Mark Forster's time management systems are interesting. Did you see Autofocus version 4? Of all the ones I've tried, it's the one I like best, though his "Final Version" system has been growing on me the more I try it.

http://markforster.squarespace.com/blog/2009/9/5/preliminary...

There's also a nice "animation" of AF4 in action: http://autofocus.cc/public/data/af4-demo.pdf

Can someone explain why something like this is better than a simple to-do list/app? I'm a fan of GTD apps because they're a place I can structure my thoughts of what's next, and see some performance metrics to remind me when I'm slacking.

However, this system seems like overkill to me. In the end, no matter what kind of system you place your "Write end-to-end tests" to-do in, you're going to have to sit down, forget about your time management system, and focus completely on writing these the specs. Reading through his blog posts about Autofocus, I get the feeling that he's sending the message that if you use this system, the actual task of writing your end-to-end tests will be easier. But it seems to me that you will just be wasting precious time maintaining this time management system, and will have less time to do whatever it is you actually need to achieve.

This is all coming from a person who hasn't tried it. Does anyone have experience with this? Do all the complicated rules actually improve your productivity?