A quick thumbs up for the Penetrator from Darryl at Cyclops. I bought a Penetrator 625 (same as the 610 with a slightly wider spread) near the end of last season and never really got to try it in a situation where it was really dark. Well this weekend I got to ride some single track in pitch black darkness. Even without a helmet light, I was able to ride close to day time speed. It worked so well, that eventually my riding buddy just rode in front of me and let me light the way for both of us. Can't wait to try it in the snow now.
If you run handguards, I found a way to mount the light such that it is out front of the all your cables and securely mounted. Find a piece of 3/4" angle and span it between your inner handguard mounts. You can then mount your light to the angle. If you need to space the angle out further to avoid pinching cables (I did on my KTM) replace your inner handguard mounting bolts (usually M8) and with longer bolts (I used 50mm bolts). Then install the longer bolts with a couple couple nuts to adjust the spacing.