mine is 10 days old... still running great. I have pushed a paperclip up there a couple times, which helped the draw. I still can't for the life of me figure out why.
It is built like a regular cartomizer, it has a wire running through the middle along with a thicker material in the middle then the lighter weight material around that, unfortunatly these aren't going to last to long. I have got about 6 refills with 80/20 juice and tried to clean them, but when I did it swelled the center material and wouldn't draw. but at 3 bucks a pop and being able to go through about 20 mils of liquid it still isn't bad.I wish they had designed it like a gogo cart, they seem to be bullitproof ..
And By the way definitely take out some filler , you get about a 40% increase in both vapor production and the flavor is increased. I have tried different lengths from 3/4 of an inch all the way up to 1 1/2 inches I think about 1 1/4 inch of material is optimum. I use 80/20 and 70/30 pg/vg mixes and this works perfect. I don't even fill a new one without taking out some filler. you can look at it like a roll of toilet paper just try to find the outer end and gently pull it up , then cut it off and push it back in then what i do is take a straight dental pick and put it in the filler and rotate it to fluff it up to the outside edge of the cylinder . the only thing you are loosing is about .5 to.75 mil of liquid capacity , which isn't a bad trade off. you will also gain a little bit of a gurgle sound when you first use the cart about 40 puffs or so but the increased vapor and flavor are plentiful. and then you also gain a better draw do to less amount of filler it doesn't restrict the center tube. If you are using a paperclip to straiten the tube out remember be gentle there is a wire running through the center tube.