I have a friend in Australia that fitted an 8xamc7135 driver and an XML to a flashlight and he contacted me to say he was only getting about 1.4 amps at the tailcap. I asked him about the battery type and it was one of the crappy Ultrafire batteries. I suggested getting some Trustfire flames but he bought a Powertech 18650 locally and the tailcap current went up to 1.8 amps.
I will also add that he paid AU$19.95 for one battery and he expected something special for that price.