This question may be a bit hard to answer, as the number given has always been an abstract percentage with no easy method of verifying its relevance or accuracy.
It certainly seems to be a bit more "precise", or maybe "exacting" is a better word, ticking down in smaller increments quicker than before.
I still use it the same way I always have, though: observe what percentage TL's start complaining about wanting a refit at, and doing my best to preempt that as the percentage draws closer.
Were you to share some of the backend numbers we might be able to have a better discussion on what various marshals find useful.