42 billion definitely seems generous. I have a couple 10K Xenotech Britelites and the specs list them at 1 billion candlepower.
From what I know, The Luxor has less than 40 of the 7K units, plus, they are using an additional reflector (i.e. each fixture has it's built-in reflector, but all the units "bounce" of an 2nd reflector) so they are gonna lose some significant output as a result.
It's definitely the brightest beam of light that I am aware of though (unfortunately not a particularly nice, tight beam.)
If anyone has any questions about BIG LIGHTS, I've got a few...so let me know.
Jason Herbert
SkyTech Productions
www.searchlights.com