I'm finding I can do the exact same build on two similar mods and one is great and the other has a lot of ramp up time, my hybrid seems to be more suited to a single coil (3 post rda) and my floating pin works like champ with dual coils (center post has separate holes). Both mech. Single 18650. Is there a rule to this? Or should I just continue trial and error. Also, I think somebody should write a book.