did mine first day Wzor released the untouched iso. Injected drivers, got key and installed. I can tell you that it's stable compared to all the problems I had with the preview (no mail syncing, blank screen after longer sleeps, no wifi after longer sleeps etc). Mail app is greatly improved and we have Outlook.
Osprey wrote an extensive how to in the same thread just recently here:
xda-developers - View Single Post - windows rt rtm
the device in Device Manager that is missing after 8.1 installation is an ACPI driver. Windows Update will give you two updates, one firmware (the acpi driver) and one defender update.
As Omni mentioned, It will stay at 0% or 2% for a while.
I would do it again.