a radiant heater heats the people in its vicinity well and quickly. this can be energy saving because you do no need to heat the whole room, the air and far objects in a room can remain cooler. you set the heater for a level where you feel good near it.
a fan forced convective heater would make you feel warm quickly if you were near to the outlet of it. you would have to put up with a loud fan. the rest of the room would heat up gradually (hours).
unless you need the air and objects in a room to stay heated a radiant heater is far more economical of money and energy.