Since my last post I have riden my by with the new lights and have to agree that the S2 gives plenty of useful light and is definitely enough. I still run it on high (2.1amps) just because my commute is short enough that I don’t have to worry about depleting the 3400mahs in the cell. On one occasion when I rode for considerably longer, I did switch to medium, and I would say it was definitely adequate. BTW, my S2 has an OP reflector.
Since getting the S2, I got two other lights as well (so much for staying under budget).
I got an UltraFire WF-502B CREE XM-L T6 from the Greed Pays thread Greed Pays ... for $3.46
and
a Tangsfire C8 XM-L2 U3 reviewed here Tangsfire C8 XM-L2 U3 Review
I tried these both mounted on my helmet. I first used the a velcro mount like this one http://dx.com/p/universal-bicycle-flashlight-lamp-nylon-velcro-clip-mount-holder-black-2-pcs-252680#.UtmGePhOmb8 but that put the center of mass too high up, and the helmet not very stable. I switched to these silicone mounts https://www.fasttech.com/p/1140013 and the 502B was very comfortable. I hardly fealt it. The C8 is a bit heavy, and uncomfarble when the helmet is loose, but when the helmet is tight (not too much, just as it’s supposed to be), even the C8 is quite comfortable.
The 502B was all right, but gave a me a bit of a tunnel vision. The C8 is a completely different story. It’s plenty bright, with a good through and spill. I would even say it’s too much light, and an overkill for what I need. I currently have the S2 on my handelbars and the C8 on my helmet, but mostly leave the C8 off. I only turn it on when there is less light and not much traffic, but mostly just for the fun of it.
At some point I may try the C8 on the handlebars, but I quite like the ability to point my head to whatever I like to illuminate.
To Garry: Thanks for the invitation. That sounds fun and if I am ever in the area, I will get in touch. Not very likely though, since we’ll almost certainly move ot of PA in the next couple of months.
Thanks again to all the contributors to this thread for the excellent education on flaslights and batteries.