Well, a late followup.
Tested for the first time in anger last week. a 4w Nightflux visionstick
totally pitch black on the backroads round our village.
The light is excellent.
A proper beam pattern like a car, and so bright. Really confident upto about 18-19mph. Upto about 22mph, ok, if you know the road well.
Car's dip for me!
I have a 1w BLT backup, and it seemed ok.... However the Nightflux in 1w mode, is about twice as good. Looks like all watts are not created equal.
My vision stick is an enduro, with the 6hr batter in full power mode. And better still it was approx £100 i remember, but £50 in a flood sale - looked brand new and unused but minus box and instructions (which I downloaded from the website).
Jeff