Nice review!
Personally, I find the fill mechanism and top cap both really big cons. I do use a unicorn bottle, but consistently deal with slop due to how you have to fill it and the lack of a secondary air vent. Likewise, the topcap lock is just plain bad, takes force and futzing around.
I vape 15ml/day, a decent amount but not too huge. This tank would drive me up the wall if I tried to use it as my primary unit.
What's really weird is this was designed by Stefan, who also designed the excellent avocado24 for GeekVape, I believe.