I've been using my new L2D on strobe for the past week or so, since sunrise is right around the time I'm riding through a tree-covered suburban road as part of my commute.

I have RESPECT for the strobe -- I can see the flashing reflections off road signs 1/4 mile away.

The other cars have RESPECT for the strobe -- I can definitely see them noticing me.

One side effect -- there is one place where cars would regularly turn left across my path, often too closely. The last few days I've noticed the cars stopping and waiting, not sure how fast I was traveling with the awesome bright flashing light. But then turning into my path anyway.

Once it gets darker I'll move to steady mode instead of flash.

I turn my strobe on and off often during a commute. One situation I turn it off for is when I'm sitting at a light behind a car/suv. Even if they were a jerk. Either that or I look up so I can try and blind some birds/airplanes while I wait

Out of curiosity, how fast is the rate of flash on that light? I saw someone on the MUP a while back who seemed to have a ~10 Hz headlight that almost made me pass out from about 30 yards.

Yes, I have 1 stop light where I should turn off the strobe.

Passively I have been strobing the jerks who pass me on a curving downhill where the speed limit is 25 and I'm definitely going 30-35mph. They then get rear-view strobed as I pretty much tail them through the rest of the downhill where there is a stop sign before a 1-lane underpass.

In any case, I am impressed by the Fenix and look forward to how it will perform when it's fully dark out during my commute in about two weeks.

it's fast, 8-10 Hz.

Too fast -- pretty dang obnoxious. Can induce fits.

I have three lights on my helmet -- two Fenix and a no-name. No-name has a fast flash but nothing like the Fenix. It doesn't induce spastic reactions. So I put it on blink.

The Fenix flashlights I either burn on medium or put on the S.O.S. flash -- much slower.

With both doing the S.O.S., I usually have one of them beaming at any moment, sometimes two. Rare instance when both are dark, the no-name blink provides adequate light for a second.

It helps that most of my route is over roads lit with street lights.

But I never use the Fenix in the hyper-flash mode. Too bright, too fast -- not very neighborly.

There's no future in causing blindness in those in command of two tons of steel.

Be careful that overflying planes don't call in the SOS signal on your behalf!

IMO, a consistent strobe (8-30 Hz, even/odd parity) front LED light is a *very, **very** bad* idea. An incandescent strobe, or rather flicker (e.g. an AC dynamo halogen at slow speed), isn't such a problem as the light source seems to go between bright-less bright, whereas an LED is Bright-off -- a true strobe effect. The LED strobe is a *major* problem for some people (myself included). A cyclist (again, such as myself) might have the presence of mind to pull over and cover his/her eyes until the noxious stimulus has passed, but a motorist might plow 2 tons into some random object.

I got my Ultrafire from dealextreme today and the strobe is also pretty obnoxious. I like the one on my cat eye better.

This is why I got the 8-mode P7. It's got 5 strobe modes, and I think I might use a couple of them on the night rides--the 3hz one in particular.

This YouTube video shows the strobe at about the 2:30 mark.