As mentioned here a few times in the past, Mark Forster's SuperFocus (used to just be called AutoFocus) uses a very different approach to tasks than GTD--the biggest feature, to me, is it's built in processing that insists on dismissing (for later review, NOT dismissed forever) tasks that haven't been touched in a number of circles through the list.
Unfortunately, it works great on paper and not very well on software, including OF (in fact, I'm here on the forums looking for thoughts on implementing SuperFocus in OF). (SF calls for cycling through the page-units, which are not very well represented in software).
http://www.markforster.net/blog/2011...uperfocus.html
Would love to hear if anyone has made the two work together!