Which is best, Exposure Joystick or Axis?

C&B Seen do a mount for Magic Shine clones these days

http://www.candb-seen.co.uk/accessories/cables-o-rings-and-helmet.html

I stuck a square park puncture repair patch on my bars for the time being and it solved the slippage issue.

Two units is definitely the way to go - not only does it offer two different purposes for the lights (one to make you visible to other road-usres and one to help you see the way ahead), but it also gives some redundancy should one fail.
I've used the Cree T6 and XML lights over the winter on local trails, they are cheap and the helmet fitting isn't great, but I reckon that the latter would be a good bike-fixed unit - reasonable battery life (2+ hours), pretty rugged, really bright... so you'd be visible.
And I agree that a helmet-mounted Joystick would be a sound investment as your main (quality) light, especially if it's getting year round use.

I have an Exposure Joystick and have had it for a few years. I ride on dark country lanes a lot and it does the job very well when the road is dry, but not so well when it is wet.
The rechargeable battery is now passed its best but we are talking regular use for 5 years+ I have now got a 'piggy back' battery unit to keep it going for hours, I understand that changing the battery is pricey.
I have also got a 'white eye' which is an extra bulb that doubles the lighting output, but hammers the battery and does not work well for long.
I am not sure if any lighting system works well when the road is wet as the wet road does not reflect light as well as a dry road?
As far as would I get another is concerned the answer is yes.
More power output? I am thinking one Joystick on my helmet and one on the bars is the way to go rather than a bigger, more powerful single unit.