I own a billow v2, goblin v2, subtank mini, and cthulhu rta. The best cloud chaser of them is... Im not sure. Definitely not the subtank mini. The cthulhu has a more restricted airflow but they all but out about the same with the same ~.3 ohm build. I would give the ease of building to the cthulhu, ease of manipulating your build to the billow, and the goblin has a slight edge in flavor. The billow probably has a slight edge in the cloud department. These are just my experiences and observations with the tanks i have used.