UTMSi is certainly related to AF4. I don't think we have declared it "superior" on this forum, though it may work better for some people.
A "natural successor" - sure, it evolved from AF4 in that it came later and adds a simple but powerful-looking modification.
This site contains many, many task management strategies. In most cases there is not a clear winner, but rather many options for various situations and temperaments. Some people report finding one and using it successfully for a long time, others switch and switch and switch.
I am about to contribute yet another such strategy! New thread coming ...
UTMS (original) was one of the most effective systems of Mark's I've tried, including being better than the other three you listed. However, I did not like the "improved" version. I do not continue to use UTMS, but I found it pretty effective while I was using it.
A "natural successor" - sure, it evolved from AF4 in that it came later and adds a simple but powerful-looking modification.
This site contains many, many task management strategies. In most cases there is not a clear winner, but rather many options for various situations and temperaments. Some people report finding one and using it successfully for a long time, others switch and switch and switch.
I am about to contribute yet another such strategy! New thread coming ...
Thanks.
UTMS:
http://markforster.squarespace.com/blog/2013/6/13/the-ultimate-time-management-system.html
UTMS Improved:
http://markforster.squarespace.com/blog/2013/7/2/the-ultimate-time-management-system-improved.html
I'm tending at the moment to move away from systems which involve a to do list as you can see from the current discussion about SMEMA.