Heat pumps have greater than 100 percent efficiency when compared to a regular resistive electric heater (which is already 100 percent efficient, when measured as heat out / energy in).
Everyone always forgets about the part where you're cooling down the outside...
Yes. Heat-pumps will make up for some losses from all other steps but I highly doubt it all togrther will reach efficiency of purely thermal system. Heat pumps also rely on access to medium that they cool down to get the additional heat and are at least as complex as a fridge or air conditioner.
What they describe is basically few twisted pipes and a tank.
I'd feel way more enthusiastic about the whole idea if it didn't involve large quantities of highly caustic 30%-50% NaOH solution.