When driving and observing other cyclists, I reckon a
flashing front light is much better seen than a fixed which, as is being discussed up thread, can easily get lost amongst the DRLs/general light 'noise' (if light can have noise

but I hope you'll get what I mean !

), so I always use a flashing front - and rear come to that, for the same reason.
With an (admittedly dimmer

) fixed light ..
just to keep legal 
.
Mounting a rear flasher high up - say on a backpack/helmet - is also much easier seen when in a car too

, probably because it 'stands out in the crowd'.