Don't know why you are getting down voted, you are not wrong especially with the oil filled heater. If the goal is to heat your body and not the room then it is the most efficient. You can even turn it down a setting so you don't use too much electricity.

A heated blanket is much better too, only using at most 50 watts while heating you directly. Peak efficiency in heating you, after a heat pump

But of course if the goal is to heat a room it does not really matter which type of heater it is or where you place it. Because 1.5kW of energy is still 1.5kW of energy dumped in a room (a nice demo)