Does the Zephyrus leak? I assumed that the raised air holes on the billow/billow v2 and orchid v6, which I have, helped with this. My main problem with the Orchid v6 is the airflow. There isn't enough. If the Zephyrus doesn't leak, this think is awesome in my opinion. Especially for beginners. It has the option of using a .3 ohm dual coil replaceably deal with japanese organic cotton. That's what I'd put in it anyway. .3 ohms. Maybe .2 if the airflow was really good and kept the cotton from burning.
Before seeing this I thought the billow v2 was a winner. It still is if the raised holes is what makes my Orchid not leak. But if they're not needed, and especially if you're a beginner, the Zephyrus.
For leaking though, your wicking (make sure they're wet but don't allow juice to flow on the deck) and PG/VG ratio (more VG, less leaking) matter. Most people say 50/50 pg/vg and wick blocking top of grooves, but not going in them works. So the normal fold over on both ends outside the coil but some extra effort added to cover top of grooves works. That's what I do.
Idk. I'm still leaning toward the billow v2.