I've been vaping for 6 months on the 510 and mega 510 mostly dripping, I have had these for 2 days. I have been pushing the boundaries on one have filled it 7 times already, still tastes like when I pulled it out of the blister pack. I have not been kind to it, I taste no burning material, wicks quickly and easily. refilling is less of a chore than dripping except for getting the second plug off initially. The contacts on some of them don't hit unless you put them on there tight. Other than having to carry a pry tool in my kit these are better than any atty I have had as of yet.
Im so happy to hear they are working for you , gives me hope, have you tried more then one, to see if your experience is consistent to a point.
Also if you dont mind me asking what kind of juice are you using.
have you tried the condom method for refilling by any chance.