I’m sorry to report that it looks like these lights are cheap for a reason: thanks to this thread I have discovered that the emitters in mine are not genuine Cree but lookalike fakes made by Latticebright.
The easiest to spot giveaway is the small square dot in the top left corner: it should be round.
One of mine even has LB written on it, as seen here:
I got mine from eBay and Buyincoins. Don’t know if the Fasttech ones are the same.