I’m up for a new Fly 6 (left one in France). Apart from the somewhat quirky OS, I’m also happy with my Fly 12 now it mounts to Exposure and not Go Pro. Just forget about the WiFi and Strava overlays.
As for battery life, well obviously being smaller, the new 12 will not last as long. And mine doesn’t last long enough already.
This Tuesday evening club ride on medium long flash I had 3:30
Last Thursday on full beam I managed only 1:50
Ride around the M25 lasted about six hours on low flash
I always ride with a back-up light, often a Joystick, but a small LED for basic commuting.
The beam pattern is basically a Mk10 Joystick.