It's really short and irritates my skin so much that it's simply uncomfortable

I loved the watch but had to return it because the metal on the band gave me a skin rash (I do NOT have sensitive skin).

Watch band irritates my skin

That band also irritated my skin

I don't have sensitive skin, I was able to wear my other watch for weeks without taking if off and never had issues

Please be aware it is not a watch for sensitive skin

Doesn't irritate the skin and flexible.

I really like the style of it, however I cannot wear it for sleep tracking because it irritates my skin

One issue I had is that the silicone band was irritating my skin

It make sense that a darker color skin will absorb more light and less light will be received by the sensor on the phone, which means low signal to noise ratio and low accuracy

I have sensitive skin so developed a mild rash on my wrist.

Of course, the window to return the item has passed, but I would not recommend I'd you're looking to use the swim feature.