Lighter than a dyno, but at 17 hours into a ride in the middle of the dark, and maybe in the rain, how well are you going to do finding those spare batteries and changing them out?
Agreed, if I were a rando guy, then I certainly wouldn't use a primary light that required a battery swap every 2 hours. But I'd consider using the S-Mini for, say, our Midnight Century. Starts at midnight, dawn at 5AMish. Cranking it down to Medium for the climbs would probably get me through with just one battery swap, or I could simply have two S-Minis and switch over when one's out of power.
Given that it's a fully self-supported ride, and basically a 6-hour time trial for me, I usually take ~15 pounds of Gatorade. The weight is a major factor already, so I'm giving serious consideration to the S-Mini approach. This is what I used the first year, plus a 2-liter Camelbak (it's an on/off-road ride, hence the XC race bike). That year, I ran a Seca 700 in Race Mode (175 lumens low, 700 lumens high), along with a Fenix L2D on the helmet for backup and reading my cue sheet.
