I just got a Cubis tank yesterday, so I need some more use before I can judge it too much.
But, my initial thoughts are, and I'm a new vaper-so take my opinions with a grain of salt:
I like the airflow adjustment.
I'm very nervous about burning with the way it wicks, flavor is okay with the .5Ω coil - not great, but okay - good vapor production - I haven't turned up over 20 watts yet.
Interested to see how the flavor is with the Clapton coil, one comes with the tank, but I don't know if replacements are available yet.
The size is nice for out and about, comparing it to the Crown is a little lopsided. The Crown is a SUV, the Cubis is a compact.