Optics for me. The Lowes task force has no business emitting as many lumens as it does. 2xAlkaline, Low-bin Cree, minimal heatsinking at best. I think its the efficiency of its Fraen optic that really helps.
The newer Lenser 3AAA:sick2: lights also really capitalize on the optic efficiency.
Malkoff M60... nuff' said.