I dont have a ufs yet but I can almost promise that when I get one I will not be using E2s in it, I have had nothing but problems with those things, I did find out that the coil and wick work good if you connect them inside of a replaceable atomizer such as the bulli and maybe even the iatty but I havent seen the internals of that yet so I cant be certain. Even if you can not remove the coil without damaging it, you can still use the wick to wrap a new coil around. Does anyone like the E2s? If so, was there some trick to getting them working properly without having to use them as a dripping device?