> http://www.difflock.com/buyersguide/newproducts/illustro/index.shtml

"a new set of bulbs need to be fitted at the same time as the unit - The
recommendation is simply because older, well-used bulbs sometimes
give up the ghost the first time that 24volts is passed through them. New
bulbs have no problem with that 'first time experience' "

Bit of a giveaway. My guess is that filaments will get to get be "older,
well-used" a lot quicker with Illustro

And I can't say I particularly care for David Lovejoy's writing. Spelling
mistakes, too many exclamation points, silly comments, and claims like

====================================================

Before we go into details lets look at some facts and figures.

Tungsten

The filament glows a yellow/red colour when a current (limited by law) is
passed through. This system is slightly more effective than mounting
candles to the front of the vehicle"

====================================================

Say what ? There seems to be no direct link to Illustro, just an e-mail
form and very few hits with Google. If buyers find that  Illustro shortens
bulb life it would be very hard to prove, and they'll either not use it any
more or accept that there's a price to pay for brightness

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