AS per topic, has anyone tried upgrading the system to Win 10 yet?
I already received the notification that the upgrade is ready on both devices.
I tried googling but no one seems to have upgraded to official Win 10 (only preview versions were reported).

Good to hear, for my switch 10...
Still uncertain for my miix 2 8, which I use as daily tab. The switch 10 remains at home most of the time.

Thanks, I saw it too. But it's talking about the technical preview version and didn't find any updated post (the original post was over a year ago) on the official win 10,

True. However the official list from lenovo (of devices compatible with win 10) does not include miix 2 8.
I am a bit cautious, since this model has intermittent touchscreen issue; who knows what it will do.