I have 3 Woodscents, and while I couldnt give you concrete info on exactly what voltage works best for each, I can tell you there can definitely be some small variations from one to another. I havent spent a lot of time trying to determine in any controlled manner which one needs more or less voltage, but I've just noticed small differences. In a sense I'm not even sure if some of the variation is also just do to different herbs being loaded (i.e. grind consistency and how dry it is), and other factors like water pieces being used, etc. I think this is generally true of all log vapes, but I've noticed certain ones can always run hotter than others, etc...
Also, I'm pretty sure that 14v is bit on the high side to be using the WS for any extended period. I would imagine ~12v would be the max to use/leave it at routinely. If you up higher briefly for soem pulls it might be okay, but I wouldnt leave it as high as 14v for a long time.