I have several brands of AA lights with good lows/moonlights. They’re all pretty-much the same efficiency.
For 1xAA lights:
Zebralight SC52’s: moonlight around 0.1 lumens (the spec is 0.28 lumens or something like that, but in reality it’s closer to 0.1 lumens). Run time around 14 days.
Zebralight SC52’s: low mode around 3 lumens, run time is a little under 3 days.
Zebralight SC5: moonlight around 0.1 lumens, run time around 14 days.
Zebralight SC5: low around 2 lumens, run time a little over 5 days.
I’ve got several other brands, but haven’t done run time tests on them. But based on tailcap current measurements, they’re all pretty-much the same. You’ll get about 2 weeks run time on a useable moonlight mode for dark-adapted eyes, and about 3 days on 3-lumen low mode. Constantly on, of course.
For 2xAA lights, like the 4sevens Quarks or Armytek Primes, the numbers are similar, but you get twice the run-time or twice the brightness, because of twice the battery.
For 4xAA lights, the only one I have with a moonlight mode is the Sunwayman D40A. It has a much brighter “moonlight”, of around 1 lumen. It seems brighter, due to the greater throw of that light, so it’s quite usuable. It lasts a little over 2 weeks, so it’s more efficient than the 1xAA and 2xAA lights. Probably due to not needing a boost circuit in the driver.
Anyway, my conclusion is that the model of light doesn’t matter, as long as it’s a decent quality brand,. They all have similar levels of efficiency. Pick a model that has the mode outputs you want, and go from there.