I have tested one that a family member has and they seem to be the real deal. Looking mainly to use in a 34ft park model trailer instead of spending money on propane. Electric is already included in the yearly fee so thats not an issue. I know the one my stefather has seems to heat his 36 ft park model with no problem...his furnace never kicks pn and the place stays nice and warm. They run just under $400. not cheap but neither is a couple 100# tanks of propane. The heater would pay for itself in less than two fall hunting seasons. If you have one, are you happy with it?