The new sleep measurement is really not good and a big deception.
First, it takes too much into account the do not disturb time frame recorded in the settings.
Let's say you specify the DND timeframe from 11pm to 7am
1. If during the week end you have a glass of water at 7:30am and go back to sleep until 10am, it will consider you have slept until 7:30am. So it's totally wrong.
2. If you wake up at 5am, you can be sure that at 6am it will still show "Sleeping" on the watch. Yet afterwards it will show the right wake up time at 5am.
3. The sleep score is not showed in the iPhone app. It seems there is no sync of the dev teams at Garmin...
4. It cannot record nap which is a big issue as naps are a good strategy to offset lack of sleep time
The first point is a real pain. I keep adjusting manually the wake up time in the Connect app but even doing that you have not detailed data" on your sleep on the added part.
The point 1 & 2 were working before the change to the firstbeat system. There are critical regressions.
I would really invite Garmin dev team to wear a Garmin watch on one arm and a Fitbit on the other arm. Fitbit is soooo much better on this.