works fine at panera, walgreens/duane reade, mcdonalds, etc.
there have been a few times where it had messed up, but that was due to my own user error. i would initiate the double click and hold my arm out, but then pull out too quickly without waiting for the haptic feedback notifying me that the transaction had been fully completed. if you wave your wrist and immediately pull away, the transaction will fail. leave your arm hanging out for a bit longer and wait for the haptic tap/audible ding to make sure the transaction was a success.