The thing is the Garmin watches sleep function struggles to read deep and REM sleep (especially REM) and can over shoot your wake up and time you fell asleep. Deep sleep is the most important I think so you won’t be getting accurate information more of a ballpark I guess. And you won’t be able to understand your own sleep cycle bc the REM is a bit finicky. If you are really serious about monitoring your sleep I would invest in the ring. I’m an average sleeper so I don’t rlly need it but my friend has a lot of sleep problems and they’re going to get one, so it depends on you. Hope that helps you choose :)