I have a Gemini Duo copy (Yinding 2xU2) which is the ‘best’ Chinese copy. The light beam is excellent and more than enough at about 1200 lumen real output. It’s also tiny.
Good run times from solarstorm battery boxes with panasonic cells.
You can get other ‘copies’ some better than others, but the Yinding is about as good as the original – get the light head only.
I’ve had it about 3 years and it’s been used in all weathers, from wet commutes to muddy night rides. I’d recommend either the Duo or the Yinding, depending upon how available they are.