When I get a 30ml glass bottle I transfer some into a 10ml PET for dripping and fill as needed. The glass I keep stored in a dark place so of course it ages much slower than what's in the plastic dripping bottle that's opened, closed, shaken and dripped from.
Anyways, getting near the bottom of the 10ml bottle of RBFS's KillRY4, and dripping it I was thinking it is pretty sweet but not as much as I thought at first. Just refilled the bottle from the stored glass bottle and dripped and... wowsa, yep it really is super sweet lol. Moral of the story, if you find KillRY4 to sweet, let it steep with whatever method you use and it will back off quite a bit.
Personally, I happen to really dig it both ways. Even at it's sweetest I find it highly enjoyable. After
vaping a couple very dry juices for a couple days (EPM's Long Bottom Leaf and Oak Barrel Cider), the sweet kick is really a joy.