I was having some trouble with burnt hits on one of the SI ones and noticed that the coil is a bit different than the origional batch I got from "the other guys". The SI one while measuring the same ohms seems smaller. I wonder if this is what is causing the burnt hits with the X2.
I raised the post slightly and it's vaping great now.
i don't have much luck with the ce3s on my x2 650's auto or manual,they give a burnt taste after a few vapes.
so i mainly use them with my 78mm's.