A bit disappointed tbh

How is sleep tracking on Vivosmart 4? I have a Vivosmart HR+ but it never manages to detect REM sleep, as mentioned by other users on this forum. Imho, Fitbit 3 does a much better sleep detection. Asking because I plan to upgrade to HS4/5.

It ... works. I put the vivosmart on the moment I go to bed (as I'm only interested in HR and SpO2 readings, but according to the manual you're supposed to put it on 2 hours before sleeping) and it sometimes thinks I'm sleeping already just because it sat still on my night stand. Also when in the charging cradle, it sometimes makes up some SpO2 readings.

But it works fine most times. And it detects REM phases, deep and light sleep just fine. SpO2 is only recorded for 4 hours, though.

It doesn't- which makes the Vivosmart 5 (and my current VS4) far less useful...

But to be fair no Garmin device has body battery true up till now. But I am positive it will be one of the next metrics for true up sync. Step streak goal and RHR was the beginning. But maybe VS4 won't get this feature which would be ridicolous as this is no feature really but just a sync. 

Still, VS5 is a joke imo. If it would have the latest HR sensor, ok. If this big band would have a way better battery, ok. But making it almost twice as big and the only new feature is something the VS4 could get but won't because of Garmins update policy is a joke. Why did they make it twice as big and still so thick. If it would be wider I would expect it to be flater if there is no bigger battery. But no... 

The only fitness feature it gained was sleep score and resp rate. Then there is only the slightly better display, not even colors like the Fitbit Charge 5. 

One question... if I am using one full day my epix 2, and another full day the Vivosmart 5, will the graphics for the full week shows the body battery for all units used together?.

According to this review the battery life is only 7 days if you disable Spo2 and sleep tracking. It would only be 4 days with them enabled. Could this be right?

See quote:

I'm still in the process of testing the Vivosmart 5, but the main downside I've found so far is battery life. Garmin says the watch will last a week on a single charge, but only if you disable SpO2 and sleep tracking. With those two enabled, you're looking at battery life closer to four days. Charging is quick though, and you should be able to get it fully juiced up in around three hours.

Unfortunately not. Sticking to my VS4, unless Garmin only enable BB True Up for VS5 only. I am also an Epix 2 user.

I'd buy the VS5 right away if Body Battery synced between the VS5 and my F7SS. I understand that Body Battery is computed on the device itself, but even though: All necessary data should be syncable, so get to work Garmin! A band for sleep monitoring and wearing on my second wrist is great (using the VS4 for now), but I don't want to break my Body Battery level. 

Floor count on VS4 is a joke.
My wife got 11 floors just walking around in a 1 floor house over a 10 hour period.
You can register floors by walking outside in an area with gently rolling hills.
And yet, in a house with 13 stairs and a greater than 10 foot rise, it misses count.
Useless, and Garmin never bothered to update/fix the problem.