OK geeks - regale me with the trials and tribulations associated with discovering the relative lighting efficiency of various modern bicycle or flash lights?

I have very limited experience - and I am sure that someone has compared their lights with respect to "brightness" and current draw. (battery run time)

My own contribution is in discovering that my Stella 120 "AA" tries to grab 700mA from four "AA"s and continues to appear bright until batteries run down to delivering 500mA.

This "test" has been repeated three times - using three brands of batteries and (2450-2600) they all power the light at these levels up to three hours. (+/- 15 minutes)

Is this consistent with other "pretty bright" flashlights or bike lights? What have you discovered?