Capital wise probably not that efficient. Energy wise it's the same as resistive heat, all electrics are 100% efficient when it comes to heating. However if you were actually looking for energy efficiency a heat pump is the better solution because they actually get beyond 100% efficiency due to how they can take heat from outside and put it inside (even when outside is colder than inside).

Also if you aren't on a green grid direct combustion is more efficient than resistive heat because of power generation inefficiency, but heat pumps can often still come out ahead