I still haven't found a practical use for it.
This morning, my watch alarm went off. Tried to double-tap to turn it off. Since my watch is still in Sleep Focus, the screen doesn't turn on, so the double tap doesn't register. I had to press the crown to turn the screen on, and then the double tap worked.
During a workout, a double-tap to pause would be nice. But no actions register during a workout.
It's gimmicky.
My AWU2 battery is actually better on 10.1.1. On 10.0 and 10.1, battery was depleting around 30% every 24 hours. In the last 24 hours, with 2 indoor workouts, it only depleted 22%.
(no cellular, no AOD, no Pulse Ox, no noise monitor)