we have three S/L 4aa led and just bought two g2L with aluminum heads. the g2l has a beautful beam with a good spot and a wide, white corona. good runtime with top quality. but, my s/l 4aa throws further and is brighter! my wife sees the same thing. we looked at the beams on white walls and also in the backyard on some trees and my shed(about 75 feet away). the corona on the s/l is smaller and dimmer. perhaps the deep reflector on the s/l is better for throw at the expense of reduced corona. running enloope in s/l and s/fire bat in the g2l. the small size of the g2l fits the pocket better than the s/l. s/l on alkalines will light up with a fair beam even when the batteries will not read on the zts tester. haven't gotten the s/fire batteries low enough to compare this. very impressed with the g2l, but amazed at how well my s/l 4aa led performs considering the cost. we are very happy with both lights, each having their place.