Mouth to lung which I run most of the time, can't replace my Kayfuns and Russian 91%'s, have 3 Kayfun Lite Clones I've ordered some replacement KFL+V2 bases for from SnailTech to get them back up and operational, 2 Russian 91%'s still going 2 years strong with just insulator replacements, and 2 Kayfun V4 Clones a year old each still running strong.
Sub-ohm tanks my OBS Crius, my Griffin, and UD Bellus tanks are running strong, been looking at a Hurricane 25mm I believe it is called, a knock off of the VCMT 25mm