I've got some KR's as well and find I still taste the filler only after a few puffs.
I fill it the exact same way and when I pop the cap off, it looks soaked. But then after a few puffs, I get the taste again so I pop the cap off... damn thing looks bone dry at the top already. So I seem to have to drip a bit in the top after every few pulls.
So i've said heck with cartos for a bit. At least at 3.7v