I've used e2's for a year and a half or since they were on rev3 whenever that was. They have been ok, far better than the filler cartos i've used. The vortex have taken a little work but I've got them working great now. I haven't used anything better yet... I may have to try the dual
coils. Other than a genisis, GG avs, and the dual coils, I've tried everything. The vortex need the center tube lifted up a millimeter and then they'll vape great. I know your pain though. E-cig attys and cartos need serious changes to make them easy enough to use for everyone. Friends I've turned onto
vaping can't deal with the maintaining and daily bull of using one. Vortex would be great in a metal tube. I like to dry burn em though so that might make things tricky. Good luck. The holy grail is elusive....