I'll use a relatively bright front light (Exposure Race Maxx on medium pointed at the ground in front of me), because that's the only way I'll be noticed at night with a lot of other visible distractions about.
I don't tend to use flashing lights, since I find them very hard on the eyes when cycling or driving behind them. They can also be very difficult to position correctly in an environment where there are no other visual cues, such as a dark country road.
On something like a FNRttC where there are other cyclists behind me, I'll try and just use two TL-LD1000s, with only half the LEDs turned on. Bright lights with new batteries are hard on the eyes, and with a FNRttC, 30+ cyclists with lights on are hard to miss anyway, you don't need something hyper-bright unless you get separated from the group (or are right at the back, which I was much of the last FNRttC, playing TEC).
Having said that, on the last FNRttC, when we stopped to deal with a puncture, I propped my bike up against the kerb and turned the Dinotte on with flash mode, which is not entirely dissimilar to a police light, you get a burst of mad flashing and then a gap. The few cars that did come along, slowed down almost immediately they saw the light, which was what I wanted with half a dozen plus cyclists standing around, and helping to fix the flat.
