I had read lots of discussion about M1 so I try to put some info to help people who want to know more.
There have lots of discussion about M1 in Mobile01 (SIG taiwan website), if someone interest about this product, you can visit, the photo I attach is come from this website. if someone can read chinese character, you may read the discussion.
http://www.mobile01.com/newsdetail.php?id=5888
BTW, I bought m1 in last month, and in my home country, most of street have street light, so it doesn't matter about the bike light is brightness or not? once you ride to mountain or the road without road light, m1 is quite impression for me, even I keep the speed in 35-40km. I still can see the road very clarify.
as I know, M1 specially in optical design, not brightness bike light but good for night rider.
I used Surefire U2 as bike light before, but get lots of argue from other upcoming rider. now I use m1, I can see the road more clear than U2, but no arguement anymore.
just like the phote, most of torch just focus the light spot, andblind up coming rider. m1 won't. m1's optical design most like car front light. not a torch. you can see the bright-dark line.
Mike