My $300 Oura Ring provides sleep and health data that my Apple Watch 7 doesn't yet. I'd really like to see Oura and Apple-Watch link together for optimum data collection. My Oura with its iPhone app, for instance, tracks body temperature variation from my normal. I can, for instance, look back on my data to identify exactly when I had my last cold (body temperature increase) along with its intensity and duration. Women use it for period tracking. The sleep tracking (the reason I bought it) tells me at any given time, exactly how much sleep I've had for a given 24 hour period, and includes such information as efficiency, restfulness, REM sleep, Deep sleep, Latency, Timing, and the like. The Oura also tracks calories burned (with walking equivalency), blood oxygen, heart rate throughout the day, heart rate variability .. all this at any point in time. I'm sure Apple and Oura have talked about joining up to some degree. I'd really like to see it happen.