The IQ-X is 100 lux (or is it lumen? I'm too lazy at the moment to look it up); the IQ-XS is 80 whateveritises.
For brake lights, if you have the ability to mount a wider light, the B&M Toplight Line Brake Plus is awesome. It detects stopping motion and brightens the taillight, in an effect similar to a car's taillights pulsing as you press down on the brake pedal. In the four or five years I've used one, I've had motorists pull up next to me at stoplights and thank me; cyclists have pulled up from behind and asked me where I got it (Peter White Cycles, as an upgrade to my Toplight Line Plus when PJW was replacing my damaged Luxos U under warranty. Rivendell's had the Brake Plusses in the past, but I think they're still out of stock).
Peter Adler
definitely not a curse-the-darkness person in this area
Berkeley, CA/USA