I'm simply gobsmacked by this light.
I just took it outside for a few minutes in the dark, and it beats the pants off my hotwires. The beam, with the 4509 lamp (Under $10 for bulb, reflector and lens) is awesome. It's a square beam indoors on the wall...but outside, it doesn't matter at all. It out-throws, by a long way, a 623, 633 and 458, all in 3-4" reflectors.
I'm gonna try a couple of Q4509s. They cost twice as much, but have 4 times the estimated life, and supposedly a much better beam. If they work as described, I'm going to try to put together a group buy to see if we can get the price down.