Which halide gives the brightest light?

[oxenholme]

Early on a Monday morning I commute to work.   The journey takes between 3 and 4 hours, and includes an unavoidable stretch of road with very severe subsidence problems.   I've been carrying two CatEye Stadium lights, and using both on the bad road, and just one for the remainder of the journey.   On good roads they are adequate, wet or dry.   On the bad road they are okay in the dry, but barely good enough in the wet.

I notice that Lupine have brought out a model that gives 5.5 hours burn time on highbeam, and uses a lithium ion battery rather than nickel metal hydride.  

Which is the brighter?   Are there any that are brighter still with good burn time?

[LowFlyingHawk]

I have a Light and Motion ARC Li-Ion light and it is very good and lasts for about 3.5 hours on the lower setting.  I loaned mine to a girl from work for a 24hr ride and she said it was by far the best light at the event.

In general, the difference between a NiMH and Li-Ion is the battery weight and the length of time the battery lasts.  The brightness of the light is the same.  The HID lights of that kind put out about 11-15W and have a fairly wide throw area of light.  I doubt you would be able to find anything brighter and/or longer lasting AND cheaper.