I found a local shop that carries the Light and Motion Urban 350 and 500 for the same price as online retailers, so I'll take a look at those this week. They're within my budget. If they're adequately bright on medium and low I might be able to use them for my longer nighttime rides. Depends on the beam pattern.

The Busch + Muller mirror used to shape the beam is very clever for lighting up the road without spill that might annoy other cyclists or drivers. So I'm still leaning toward the B+M.

I've mentioned before the inexpensive Vivo-Bike Illuminati uses a similar mirror design to shape the beam. While not as smooth as the B+M, it does project a beam pattern that's bright enough to see the road ahead at my usual pace (I average 12 mph in daytime and only 8-10 mph at night). Normally I use it on flash in traffic, day and night. I've tested the Illuminati on video at night, and the beam pattern is tight enough that it can be seen from the front and sides, but suddenly gets very bright when aimed directly into the lens. So I can avoid blinding anyone by mounting the Illuminati on my helmet, aimed downward at the road ahead. But by lifting my head and looking directly at a driver I can see they notice quickly and will pause before leaping into traffic from a parking lot or intersection. It's nearly the perfect to-be-seen light for helmets because it weighs almost nothing. But it's not quite bright enough for riding faster than around 10 mph at night, and lasts only an hour or so on steady bright. On longer nighttime rides I'll use it on flash to prolong battery life, but switch to steady bright on tricky areas such as dark underpasses, etc., then back to flash.

Last night I rode for several hours with a friend who uses a popular standard type handlebar mounted headlight, and the flasher wasn't nearly as effective as the Illuminati -- it's not as visible from the sides or as bright on flash. And on steady it casts a typical circular pattern that might annoy other cyclists or drivers on steady bright, unless aimed downward enough to compromise lighting up the road well enough for the rider to see effectively.