Well thanks for the updates and corrections - clearly most of the posts of this thread are from the veteran night-riding/commuting community.

The origin of this thread came to mind as a result of another "what's the best head light for "x-dollars?" posting.

And of course my one-track mind wanted to create a stream of thought that realizes that using up your bicycle lighting budget on a high quality, yet singularly-used headlight leaves the cyclist in the same precarious condition of anyone using a single headlight, cheap or expensive, - that is - unusual, yet possible catastrophic failure of the the light OR it's power source.

So anyway, if this thread results in any "newbie" being schooled about the need for a backup light or a dual tail light setup when thinking "new bike light" - then my work here is finished.

If other cyclists are content and confident of their single-power-source lighting systems -so be it.

As we all know - in the post 911 world - the facts change as we encounter them. (sarcasm intended)