I have owned 4 of these in the last 2 years, two were warranty replacements. The battery door is a huge design flaw as it is the battery negative contact and relies on the hinge to be part of the circuit. Once the hinge builds up resin, the circuit is broken and the unit starts to fail. Cleaning the hinge is difficult as you can't really get in there, it doesn't come apart and you must rely on using drops of isopropyl alcohol and "working" the hinge back and forth to clean it. This won't last and you'll be back to doing it over again, and again until you spend more time cleaning it than actually vaping with it. Eventually it just won't do what it's supposed to anymore and it's back to time consuming warranty claims with endless back and forth emails telling you to try other batteries, cleaning the hinge again, sending videos and pictures etc.
What I do like about it... you can swap batteries, the optional herb/extract "pods" and their hydrotube attachment ...All 4 have failed though so it's time to move on. A redesign is possibly the only way I would come back as they are actually great when they work.