Never used Apple Watch, my GF had v3 for a long time. I ordered a Withings sport a while back and when she saw that it tracks pretty much the same stuff, has notifications and doesn't need to be charged for 20+ days she got one in a week. I remember a couple of instances where she would forget to charge it and didn't have the charging cable with her - probably less of an issue with newer models and wireless charging, but anyway she said it was annoying to keep track of another battery.

People are saying "charge it during showers" - IMO that's just too much inconvenience for no benefit - I shower in the gym - do I go and charge it then ? Or when I'm tired and want to go to bed - another thing I can easily forget. I like the idea of a smartwatch - would be nice to have a better screen and more rich interface than my Withings - but sub 3-4 days battery is a no-go for me. I've seen some smartwatches that fit that criteria tho - so will need to do some shopping around and see the tradeoffs

Sleeping with it on is like half the reason why I wear a wrist watch in the first place

I sleep with it on (sleep tracking app) and use it all day -- I charge it for about 15 minutes twice a day while I shower in the morning and as I get ready for bed only.