6 sec a month is really good for me.
dont mess up with the trim screw... an info for you, quartz accuracy is depend on the temperature...
a have a g-shock that +7.5 sec/ 30 days if not worn.. i experimented by wearing it 24/7 even when i sleep, and in 16 days its only +1 sec fast than time.is.
and i have one that +4.5 sec/30days, and when worn about 8-10 hour a day, in a month its only less than +2 sec.
trimming for accuracy need patience and lots of experimenting... (even though sometime you got lucky =)
an info for some one thats gonna trim latter. after trimming, its better to remove the battery for some minutes and do AC reset since after trimming the quarts would nt directly change... it store some of its power in something like reserve capacitor so, it might take hours/days before it change the frequency.. pressing some light also help direct the current from the capacitor reserve.
i know its hard to explain, sorry since english is not my first language...
i know these all from my own experimenting, so i hope i'm not offending anyone.
i have seen some post about trimming accuarcy went wrong... i also have read when sedi trimming his G7800 and got some "funny" behavior.
i have succed in trimming my g-shocks, in my book +2.5 to +5 is the goal.
have a great day guys.