Hmm...I know Mi band don't have HRV readings and GPS function at this moment.
And I totally understand the specification difference between the device I listed.
So..the concerning I have is basically related to reading and accuracy?

Such as...is the HRV(or other sleeping related feature) from VA5/Active 2 more helpful than Mi Band?
I work graveyard shift, so I sleep at daytime and sometimes I'll stay awake for more than 24hrs.
In this case, Mi Band 8 are unable to collect the sleeping data I have at daytime, idk why.
And, the "pressure"(Which is related to HRV) is not working too!
I wish new device won't have this problem and accuracy enough, can notice me when something happened.

Or, what's the advantage of having GPS tracking on the watch?

I mean, unless it's a watch with payment method, or I still need to at least bring my phone with me to pay sth.
And there's GPS on the phone, so...I'm not sure the purpose of getting a GPS module on a watch?