I have an Evolva. Awesome. No idea on true output, but for a self-contained unit with only two 18650 cells, it lasts an age on full power and is plenty bright. Enough to easily get a 2.5h ride in Chopwell or Hamsterley without the power LED dropping down to red.
That’s compared to a SS X2 (ish?), another Chinese thing and an Aldi 4 LED unit.
I use it on top of my Super 2r after getting a tripod thread to go-pro mount. I’ll be getting another for the bars so I can retire the other lights.
Only thing that isn’t so good with the Evolva is that the thread hole for the mount is behind the centre of gravity, which would be a pain for bar use with the supplied rubber mount.