I'm curious what dyno light you have seen from behind. I think the Secula is good enough, and most others are okay. Not that I doubt your statement, but even on PBP, dyno taillights are in the minority. I doubt there are 1000 riders with dyno taillights on that ride, maybe just a few hundred. I have seen way too many riders take off from the start of a 300k or 400k with extremely dim battery lights or even lights that don't make it more than a few miles before giving out. So basically they are guaranteed to be dark from the rear for a couple of hours on a ride. Even my dimmest dyno taillight is brighter than those. Having said that, I use a blinky as backup. I wish there were blinky dyno lights, but apparently the market is too small.