I have 4 Orchids and the Billow outperforms them in every way, including flavor. It is picky about the build, so keep playing around until you get one that works. So far my best flavor build has been 0.5 ohm using 8 wraps with 27ga. kanthal around a 2mm (5/64") mandrel centered directly in line with the air holes about 1mm above. You can also use 2.4mm (3/32") but if you move either just a little too high or behind the air hole you lose flavor quickly.I'm not thrilled with my Billow's flavor even though I love the same build in my Orchid, 0.4 ohm. I'm going to rebuild it this weekend and try 0.6 ohm. Do you have an Orchid? If so, how are you finding the Billow flavor in comparison?
Hopefully in the not too distant future I'll be able to see if this build works with the Aqua.