I have heard of them and surprisingly MOST of the fiqures from the article are correct. Except two:
The cost to operate a conventional water heater and by extension the cost for the heat pump water heater.
The actual measured cost to operate a tanked heater in TV, at SECO rates is 13.00 to 16.00 a month.
That completely blows the economic argument away. If you want to know what appliances in your home cost to operate and not rely upon someone else's advice get
Sense: Track energy use in real time to make your home more energy efficient.