When I got my topbox nano I used the vertical coil that came with it. It was a 1.2 coil and was awesome at 12watts with just a bit of airflow. I also got a box of 1.2 coils, but these turned out to be horizontal coils (guess the older ones?). When I use that one I have the watts turned up to high for my liking to get any vapor and flavor at all and more airflow. Have since ordered the ss coils and waiting on those, but why such a huge difference if they are both 1.2 coils? Hope this makes sense to someone.