That is indeed part of the torment!
I got the Rhythm 24 yesterday and tried it last night. It worked! w00t! I had to put some tape over that blinding blue strobe light and it’s going to take some time to get used to the sensation of it on my arm; I found it to be the most comfortable just above the elbow/below the peak of my bicep. I love that it stayed mostly dry during my ride this morning; my HR straps get drenched! Like a dummy, I left it in HRV mode last night and it barely had enough battery life left to get thru the ride this morning.
On the FitBit subject, I have a Charge 3 but stopped using it. It’s the best of the several fitness trackers that I’ve tried, but the cons outweigh the pros. For me, the live HR tracking throughout the day proved to be very accurate once I got the strap adjusted properly. The notifications and contactless payments (even w/o the phone nearby) were also nice. I also really liked its ability to detect when I was fully awake vs sleeping in the middle of the night, tho I have my doubts about it’s detection of the various sleep stages.
The Charge 3 does a really good job at step counting. When comparing it directly to my Fitbit Zip (which I wear on my shoe or on the hem of my shorts), the numbers are quite close and I’ve found the Zip to be extremely accurate. However, the charge get’s soooooo many false positives during the day that it often ends up reporting 3 to 4 times the number of actual steps take… and it uses steps as part of its calorie burn calculations, so those numbers end up getting skewed. I’ve had it count thousands of steps while I was sitting at my desk conversing with people (I do gesture a lot). I’ve also had it count 15000+ steps during some of my long bike rides, and the app is not smart enough to see that there’s a conflict between those steps and that ride over the same exact period of time (after importing it from another service). It is possible to put it into “cycling” mode during that time, in which case it won’t count calories for those false steps, but it WILL still count the steps… and if I forget to do that, I end up, I sometimes end up with a 6000 calorie day.
Back to sleep tracking, I wore the fitbit last night and also used SleepAsAndroid with the Rhythm 24. There was a point at 11:00ish where I was definitely awake and moving around (and looking at the clock). The FitBit logged that as a brief awake time. SleepAsAndroid shows a strong motion and HR peak at that time but thought I was in a light sleep. At 12:42am, I got out of bed to pee and got back into bed at 12:45 am. The FitBit shows this as wake time and even counted my steps. SleepAsAndroid shows a massive motion spike over that period and even has recordings of me getting out of and back into bed, but had me in a light sleep the whole time, followed minutes later by REM sleep. SleepAsAndroid reported 6:19 total sleep time while the FitBit reported 5:47; I feel like the fitbit was the more accurate one in that regard.