FandyFire, not threaded dropin.... http://www.dealextreme.com/p/fandyfire-f-3800-xm-lt6-1-mode-2000lm-3-led-white-flashlight-1-x-18650-2-x-18650-3-x-18650-92125?r=43033281
1 Mode ONLY???
mmmm... Voltage input - 10 to 22 volt?¿¿??
And a light meter (mini)... http://www.dealextreme.com/p/dt-86-1-5-lcd-mini-light-meter-1-x-9v-82794?r=43033281
I think the boost drivers are not doing very well at all. Actually even those from the branded flashlights have a higher return rate. It is size-to-power ratio. Those in CPF are crazy with their TK70, gun and gun the light in Turbo 2200L OTF for over an hour and making the head too hot to touch (that means the driver as well). In thaicpf you see this is well over 50 deg C for the exterior @ the head. Not good. That light has a system power of about 35 watts.
So far my trustfire TF-3T6 is pretty ok. It does not boost a lot during the end, just steps out of regulation. I think that saves it from quite a bit.....plus the 2.1A run. I have clocked about 10-15hrs as of now. I also put heatsink compound on the threads.
MY 3 x DRYs are a-ok even with the crazy abuse. (well i have 6 backup drivers... so can "afford" that)
It does boost at the end, it just doesn't try to regulate power instead of current. That seems like the way to go instead of going all the way to 4A+ just to maintain brightness.
It goes like this.... it slowly creeps up and hits about 3.7A, then suddenly goes up very fast for the next 15 seconds, believe it hit 4.5A. Could be cumulative effects of 3.7A long terms further excerbated by over 4amps for 15 seconds, plus the small driver/components sizes without heatsinking.
In LPF, the guys usually heatsink the driver, with coins, etc... The laser diode is usually ok unless you drive the heck out of it.
you can buy spare driver if needed but you should not need it Triple T6 Cree Circuit Board Driver you can use the cail cap switch, bezel, glass lense, o-rings and extention tube from the TR-1200 if you damage the light externaly
but i would get the 3 X 18650 its claimed it has 0.5 amp higher regulation and it gives you longer run time and more options, you can run the light for 60 min's no worries