noglider 

Yes, I usually use two tail lights. On my Volpe, I use the dynamo powered steady tail light plus the Hotshot. On bikes without that dynamo light, I use two Hotshots, aimed out slightly or a Hotshot and a Planet Bike Superflash (PBSF).

I think I should write a blog post about my night time visibility approach, since I mention it often enough.

rfomenko

Hotshot used to be my only light when I adapted its mounting to PBSF bracket and I kept PBSF as a backup. However, I realized that PBSF is not really good enough for daylight, didn't like its AAAs & no reflector. So now I got the latest version of Hotshot Pro 80 for $45 & it's the best taillight under $100. Ordered some extra brackets for it from Cygolite & now I use both just like you do. Always wanted to try dynamo but it makes no sense in my situation because I do not really need a bike for commuting (living next to SI Ferry & working in downtown). Some day perhaps But I have one bike set up for shopping (Raleigh) & Serfas is a perfect light for its rack. The shopping distances are short & I do not really need a back up light for that.

T Stew

AAA's really annoy me. Unless the device is really small, no reason not to go with AA's. They hold 3X as much energy for only being a little bigger, and only slightly more expensive too. 2 or 3 years ago I got a Portland Design Works Danger Zone tail light. I'd be surprised that there isn't something much better now, but it seems very bright, with a just wide enough beam to work well on country roads around here. I actually bought it for running, and clip it on my headlamp's band on the back of my head. I was wearing it one day that was very overcast, and an old fella driving a truck slowed down as he went by and actually complimented me saying that it really helped him notice me. Thought that was pretty cool. Only wish it took AA since I've got a bunch of them.

I'm a big fan of Zebralights and have 3 AA headlamps and one 18650 headlamp of theirs. Fantastic lights, and while the beam isnt ideal for biking I find the 18650 powered headlamp to be plenty bright enough. I thought about their red headlamp, and using it as a bike tailight with a TwoFish Block, but it's a lot of money just for that (I wouldn't use red for much else really). 100 lumen on max, strobe mode. H502r Red AA Flood Headlamp it is an open emitter floodlight with no reflector, so a very wide even beam but no focused bright center. Even at 100 l I'm not sure if it would be really bright enough being a true floodlight.

rfomenko

I like 18650 lights too. As of AAAs, I'm getting rid of bunch of them. Still using a Lezyne Super drive that takes 18650 & loving it. Too bad they went with proprietary batteries now. And if I needed a new front light right now, I'd get this: Fenix BC30 LED Bike Light - Fenix-Store