Okay now going to the other extreme.... Bottle dynamo? Anyone used one. Cheap and a good backup? Could be used at dusk to save battery. Used in conjunction with normal 800 lumen lights to give better light output closer up. Anyone used one in all weather conditions and can tell me how they performed. Noticed that a lot of tyres have a sidewall designed for a dynamo.
I replaced the last bottle dynamo on my own bikes about 3 years ago, still got them on the 2 visitor bikes and one of my wife's bikes (these 3 bikes hardly ever used after dark, not used for commuting in traffic, so no real incentive to replace the dynamos).
Nordlicht dynamo was used in all weather conditions for at least 12 years on my commuter, no slippage problems as sometimes happens with bottle dynamos. Plenty of output for modern LED lights. Downsides compared with hub generator - noise, noticeable drag.
With hub generators I tend to leave the lights on all the time for commuting - the extra drag isn't noticeable and I reckon the slight extra visibility is worth having.