Low voltage lighting is very popular in art studios because the light it produces is "true light" which means it doesn't distort the colors of the art work. It is as close to normal sun light as possible.
About 15 years ago I was told by a lighting rep that MR16 lamps were better because they were more efficient. I never did see how that figured.
More expensive fixture
Special dimmer needed.
Hotter fixture that burned the lamp socket.
similar lumens per watt as to PAR halogen lamps.
So I ask where is the efficiacy.
There is a contractor in this town which thinks that Low Voltage Halogen puc lights are energy efficiant and Qualify for Ca Title 24 for Kitchens and such!