help compare Energizer hardcase LED light...to Quark AA^2?

I'm wondering about the energizer hardcase reviewed here by light-reviews:

http://www.light-reviews.com/energizer_hcp_4led_headlight/

I'm having difficulty comparing the relative efficiency between this light and something like a Quark AA^2. Part of it is because light reviews did the energizer review in terms of light intensity of the spot rather than total lumens OTF. Also, the energizer uses 3 AA, making the comparison more difficult.

If I compare the lumens vs runtime of the energizer (XP-E, resistored circuit I'm guessing) to something like the Quark AA^2 (XP-G, boost/buck circuit), how much more runtime does the energizer get? Or, how much better is the Quark relative to the Energizer, trying to normalize for the Energizer having 1 more AA battery, and for the difference in brightness?

I also realize that the Energizer runtime plot isn't a straight line and lumens goes down over time...but even taking that into account?

Also, another more EE question. Am I right in assuming the Energizer is a resistor circuit? Does having 3 AAA remove the need for a boost circuit?

Thanks for any advice!