As far as I know Halogens are simply brighter because of the halogen gasses used in the light. They allow the filament to be ran hotter. Dimming a halogen even slightly drops the filament temperature back to the level of a common incandescent bulb.
Buy an incandescent bulb and use that. Just think of it as a factory made pre dimmed halogen!
Dim is simply less lumen's output. Less lumen's comes from less power input. Why dim a 100 watt halogen down to the output of a 60 watt bulb when you can just by a 60 watt bulb and save yourself a load of time effort and money?
Get a light meter and do an honest test of brightness. I bet the smaller bulb at normal power puts out the same light as the bigger light that is dimmed to its same level of brightness.
I go through energy savings arguments about every two weeks with someone who read something on the Internet and either believed it was true or simply misread the information or most often flat out did not understand it!
I have an associate that I did a home energy use audit for. I had him change out all of the lights he had from standard to CFL's.
It cut his KWh usage by around 25% in the first month.
I was at his place some months later to do another one. His bill doubled for unknown reasons.
He read or heard some place halogens were more efficient than CFL's So he switched his whole house over to them.
I asked him why. He said they give off more light and are more efficient than regular bulbs.
I told him yes they are more efficient than regular bulbs but going by lumen's per watt they are about 4 times less efficient than CFL's. I showed him the numbers on the boxes.
He said but the lumen output ratings are higher than the CFL's!
Well of course they are! They use far more wattage than the CFL's do.
The watt meter just measures wattage and could care less about what type of load you have.
Now he is back to CFL's again.