I think i've found a tank I like. I love the convenience of a carto but I don't like what the filler does to the flavor so, mostly, I've been dripping again. These don't have any filler, they don't leak (unless you are an idiot like me) and they are really easy to fill (when you take off the top, the space between the center post and the side is wide enough to sick the tip of a bottle in.)
I've got them through the Health Cabin co-op. I've only had them a couple of days and I haven't tried changing coils yet, but if it continues like this I will be happy to settle on these permanently.