I got a new fenix 6 sapphire as a replacement to my fitbit ionic. I must tell you that the sleep tracking is not even near the ionic.. For the amount of money it should be doing it better than the fitbit. For example.. I went to sleep after 1145 and the app showed already in light sleep at 1125 and also woke up a couple of times to open the door in between and the watch didn't get those times.