In your opinion, whats the "best" under $50 single led light available at DX that uses two 18650's. I've looked at the Ultrafire WF-502D, the Romisen Cree RC-J4, and the Romisen Cree RC-D4. By best I am thinking in terms of efficiency, brightness, runtime, and size, (and somewhere down the line modding). Is there anything better that I have missed, thanks for your help, I've been looking at this and just can't make up my mind.