but what I think is the issue here, is more the time cycle of the review than the gradation itself.
what I find critical is not "to have or not multiple gradations", but that it allows that, at a certain moment, after all the comparisons made, I can have a period of time (be it 20 minutes or my whole day) where I can trust some fixed guide without having to make any decisions for a little while... and that's when you don't want a lot of new inputs questioning your previous decisions. mental resources of decision and mental resources of execution are very different and avoiding shifting between them goes a long way in terms of efficient use of brain power.
(I must confess that though i'm really really new at this forum, I'm positively overwhelmed by the amount of knowledge, and value that I already got from these first dozen of discussions I've "attended" so far. Thank you forum and everyone!! Pure gold resides in here...)
Gonšalo Gil Mata