Well, it does depend on where you are. I agree there are places in China with terrible air pollution, but Shanghai definitely isn't one of them - I think the air here is reasonably clean for a city of nearly 25 million people, and has noticeably improved in the more than 4 years I've lived here

I'm running a pair of 18650 powered flashlights on my commuter. I didn't go for the super powerful ones simply because I rarely venture out of the city into places where there isn't a lot of street lighting. The lights I've got are plenty bright enough, and I'd imagine even on a dark road they'd do reasonably well at full brightness too. The double U shaped mounts are excellent - plenty of Shanghai streets are pretty bumpy, and I've never had a light come even close to popping out going over a bump.