I have a few RTAs of varying designs but want one specifically for single builds. The two I have my eye on at the moment are the Wasp Nano from Oumier and the Serpent Elevate from Wotofo/SMM. Questions for users of either or both of these tanks: Does the top-to-bottom airflow on the Serpent actually work? Which, if either, is more forgiving of inconsistency in wick tightness? Which is easier to build, particularly in regard to pre-measuring coil legs? Which works best at low power? The benefit of your experience is greatly valued.