I have posted on this before but cannot remember the thread just now. Many of the Chinese flashlights advertise the total system power useage which is not realistic to the power on the LED. Additionally a business associate of mine in China who exports flashlights has explained to me the acceptable marketing practice that loosely translates to English as "exagerated wind". He told me of an incident that happened this summer. A manufacturer showed him a competitor to the venerable 7 watt Goston and tallied up the power and called it a 12W. That week a competitor announced a similiarly built light and called it a 15W. Now remember the lights are the same so the producer of the 12W recalled their lights and held shipments then renamed them all 16W lights. My friend was beside himself, but that is how business prospers in some markets.
In the US we usually rate lights by the power consumtion or output of the emitter. Most of the Chinese lights are either 1W, 3W, 5W LEDs or clones of the K2 which is I think a 6.5 watt. If they are overdriven, yes, they can have a higher rating in actual use but that rarely is the case in relationship to the product description. Over driving does shorten the life but on the overall life spand you are more likely to wear the light out, the switches will break and you will batter the thing to death before you burn out an overdriven LED on a commercially massed produced product. The expected life of LEDs is so long over driving is OK.
You mention two places, must be QualityChinaGoods and FifthUnit. Both have greaat reviews on CPF. Both post beam shot tests. Look at the actual test pictures and make your choice. Choose by light output numbers, those are usually correct and not inflated.
One thread on CPF was about the new K2 12 watt. One vendor who tested it stated that the overall output on the high mode appeared less the the old Golston 7w. Lux readings on the light on QualityChinaGoods is slightly higher for the 12w than 7w. But if you look at the beam shot, the 7W is wider. The same reflector is used and there is a difference in geometry of the two LEDs. So, a wider beam will have a lower intensity, lux, reading. Makes sense? So I find I need a little wider throw than the 12w and that means the 7w puts more light where I need it. If you need a little more light on a smaller area the 12W would give you that. This type of comparison goes accross the board for all those lights you listed. Again look at beam shots, size of the spot and the lux reading and balance what you need. Hope this helps. I know the lux readings and beam shots on QualityChinaGoods are done by that company themselves, by our member DAE, and are reasonable and accurate enough to be very fair. I believe FifthUnit has their own comparison program too.
