Don't be fooled by advertising claims that one type of electric heater is more efficient than another.
All electric heaters are 100% efficient at converting the power to heat, what may be different is the relative proportions of radiant vs convection vs conducted heat transfer.
Contrary to Woody's answer Quartz and halogen are different in the wave length of the radiant heat they produce. Quartz tend to be longer wave lengths (redder)and halogen shorter wave lengths ( more orange and yellow) How ever thy both are designed to produce radiant heat and only the items teh light falls on will actuality gain any significant heat.
I find them of most use for heating the awning, you get light and the heat given off heats you directly and therefore instantly, rather than waiting for other type heaters to heat the air before you get any benefit.