Consistency is the quiet killer of repeat sales. A device that hits well for the first fifty puffs and then fades is a disappointment, even if it's rated for thousands. As a staff member, you want a device that behaves predictably. How do you judge this without using every unit yourself? Ask your distributor for a sample or check batch quality. In the WINDBAR lineup, the VERTEX-VISTA and VERTEX-25K are built for consistent draw and flavor delivery, but you should test them yourself. A simple habit: when you open a new box, take one unit and use it for a day. Note if the flavor weakens or the draw gets tight. That's your baseline.