I recently installed a bunch of these in my home and was pleased with the much lower heat production, compared to the old iron trannies. I was prompted to replace them, whilst doing some work in the ceiling and, after touching one of the old trannies, was horrified at how hot they got. Anyway, here's my measurements on the new vs. the old trannies (it also explains why the lights seen somewhat brighter than the old):
All measurments performed at 240 VAC.
Old tranny: Output Voltage: 11.4 VAC Power consumption: 64.7 watts
New tranny: Output Voltage: 12.8 Volts Power consumption: 56.4 Watts
A good thing. Dunno about the lifespan of the lamps, given the higher input Volts though.
Some more nice things about the Crompton kits, which use the Possum trannies:
Silicon leads for the lamps. A nice gimbal mount The lamps have a glass cover. I like the cord clamping on the Possum trannies. A clever design.
The biggest win, however, has been the replacement of the 120 Watt lamps in the bathrooms, with some Phillips 23 Watt compact fluoros (the ones with the curly tubes). VERY impressive light output, with almost identical spectra to the old incandescent. Highly reccommended. 8 Bucks each from Bunnings.