[shootniron]

Also, ad to this equation, that the tac light is often used more for other uses than it is tactically...so you may want a light that serves the other purposes well, too.

To answer your question, lumens rule the day for me now as this is the primary descriptor assigned to most lights now and it is easy to understand and see the difference for me as I am mostly uninformed as to what most of the specs on flashlight mean.