I do get reasonable vape but find there is more vape when I put the abv in the volcano. Still I don't feel that a 300 dollar unit should vary wildly so much so that my technique should need to change based on the particular unit. You have not convinced me that I should expect such a wide variance and I do think the amount of time to shutoff would be a good indication on how long the unit takes to heat to 400 degrees. If it takes longer the coil could absolutely be positioned wrong so that it does not fully heat the bowl but instead finds a different path to trigger the heat sensor which would be why it takes more time to trigger the sensor. Why would this not be the case?