I tried another build this weekend. Went down to 2.5mm ID, pulled the coils closer to the air holes, and changed to KGD instead of Rayon. Same .4-ish ohm. Going back and forth with a closed or open top air flow and how open to have the bottom holes. I switched to the KGD because it seemed the rayon wasn't holding the juice long enough. The flavor production is very, very good. ETA: I especially like the ability to adjust the top and bottom air holes without taking it apart. Easy to tweak.