Actually, halogen bulbs produce a greater % of light, with less % heat, than a conventional tungsten filament bulb, so they are more 'efficient' = more light for your dollar to the poco. Trouble is, we tend to fit more of them - dichroic bulbs are directional and can leave 'pools of darkness' unless used in numbers. They do also last longer. As to the humble pie, the transformer losses must make the 12v versions less efficient, but efficiency sells naff-all today, what we want is the "look". Quite right too, who wants to live in a cave?
Alan
