That's my gripe with both Siri and Double TapMy biggest complaint with double tap is that I have to wait for the screen to “wake up” (go from dim to bright) for it to work. By that time I’ve already got my other hand over tapping the screen. And sometimes typing triggers it, another annoyance.
They do work most of the time. But neither Siri nor Double Tap registers any input unless Watch has just been waked by either raising my wrist, tapping the display, or moving the Digital Crown.
But exactly Double Tap and Siri should take input either all the time. Or really just a few seconds or minutes after the display has dimmed.
Yes, I get that it's supposed to automatically dim and go into a sort of semi-standby mode when I lower my wrist or haven't interacted with it in a while.
But Watch to me is particularly useful for hands-free gestures that I'd otherwise have to pull out my iPhone to perform.
But being that Watch often dims after even the slightest movement of Watch, or delay in my response to a notification, Siri, or Double Tap prompt, I often have to use my right hand or press my Watch against my face or nose to wake it and let me use Double Tap or give Siri input.
Really kills a lot of the convenience that Watch could offer if the raise-to-wake and "lower-to-go-into-standby-mode" algorithm was better or could be tweaked by the user.
But actually, this would ideally just have been a simple algorithm that, over time, learns the users usage patterns to more accurately know when to go into standby-mode(dim the screen and stop taking input) and learns what the user typically does in an app or as a response to a notification, Siri, or Double Tap prompt in order to avoid going into standby-mode too soon.
When I heard that S9 got a new SiP and upgraded internals, I really thought that was to improve Siri and Double tap.
But it's not better than S7 or S8 from what I've seen irl.