Some features fail worse than the current government. I walk up the stairs 10 times a day, and the device registers only one. According to this device, I'm completely stressed all day long, even when I'm watching TV on the couch, and when I exercise, my heart rate spontaneously averages 25 beats higher than with the Polar heart rate strap. (I have much more confidence in this). In combination with the same strap, it does work. You have the strap's readings on your wrist at a glance, combined with your training schedule. An ECG monitor will be fine. Respiratory rate definitely not. Try the heart rate coherence function, for example. Using your watch, you get a respiratory rate of 6 per minute. The device shows 15.
For me, it's only suitable for exercise in combination with a Polar heart rate strap. It's fine for daily use, but don't take it too seriously. Connection with Android is fine, by the way. Now you're also bothered by all the easy-to-read notifications and messages on your wrist. Oh yes, the phone function... you have to be very hearing, but it's still comprehensible. The other party understands you as if you're talking into a tin can with a string attached, barely.