[inetsee]

I used to have a FitBit that I wasn't entirely happy with. After some health issues, I recently upgraded to a FitBit Charge 5 that I'm mostly satisfied with. It was quite inexpensive; I got mine for $99. It does continuous heart rate monitoring, but I have doubts about the accuracy of its resting heart rate calculation. It has all of the "interesting sensors" you listed, but I haven't explored them all. The one feature that decided me was the ElectroCardioGram (ECG) function. It's not perfect. It requires that you sit very still for 30 seconds with thumb and forefinger grasping the sides of the FitBit, and it only checks for A-Fib (Atrial fibrillation), but there aren't that many fitness bands that have that function, and it was important to me to get one with that feature.

My biggest disappointment with this band is the sleep tracking (which was also a failing with my previous FitBit). I have to get up at 7:30 to feed my cat, then I go back to bed for an hour or so. Both my old and my new FitBit record 7:30 as the end of my sleep period; they ignore the sleep time after 7:30. I'm also not convinced that a band you wear on your wrist can accurately track REM sleep.

I use the FitBit app for some other features and controls, but I have no idea about "Open data access, reverse engineered APIs, 3rd party data analysis apps".

All in all, I'm happy with my FitBit Charge 5, and I think it's a good value for its price.

[gardenfelder]

Rem sleep is typically measured in a sleep lab with many sensors, including EEG sensors - which do not exist on the wrist devices; inferring Rem is thus difficult. To me, it's just a kind of "relative" reading: think "rest state", and I care about it changing from time to time.

I upgraded to a Charge 5 from Charge 4, even though I happen to own an iWatch as well. Big mistake.

Charge 5 is happy to beep sms (morse code) from time to time when my cell phone picks up text messages. In the day time, that's fine, buf 4am in the fucking morning? There's no damned way to turn it off.

I am not aware of a skin temperature reading on it, though it does do an EKG-like reading, just like the iWatch. No clue whether it will phone 911 if my ticker gets funky; iWatch is known to do that.

I think I'd rather go back to a Charge 4, if only to get rid of text messages. I really don't need them - especially in the middle of the night.

[deepsun]

Wow, interrupted sleep every day is not good. Maybe auto-feeder once a day would help?

[inetsee]

My cat is quite insistent. You really don't want to cross her!