Two successful installs so far on my Venue 8 Pro (5830). The first was last Thursday using the media creation tool "upgrade this pc" option. I freed up 10gb of space in advance by using disk cleanup, ccleaner, and removing large apps (HERE'S TO YOU HALOs' AND HITMAN GO!). BTW just go ahead and uninstall office, since you won't need it with the new apps. Regular readers know that the new "Mail & Calendar" apps are essentially Outlook. Combine that with the other Office apps and you'll have a smaller install footprint. ;-) In the end, the upgrade took about 90 minutes.
Pros: Almost Perfect upgrade.
Cons: Live Tiles! They'll all be there in Tablet Mode, but.....they're just clumped together. You'll have to reorganize them yourself. :-\
Second Install was today. This is where it gets tricky. For a clean install, you will need a OTG adapter, usb flashdrive, powered usb hub, keyboard & mouse! Also new drivers from Dell dated last week. It's a set of three, BIOS 5830A11, 5830 Intel_Chipset_Driver_67YC3_WN32_603.9600.2067.27988_A00, and 5830_Network_Driver_RJCFP_WN32_3.7.2.59_A00.
For the OTG adapter, I suggest finding one that comes with flash memory. That way you use it to make your bootable Win10 installer with the media tool, but also it can be used later to backup the tablets recovery partition for more storage.It also will work as a OTG usb adapter for anything else. ;-) .
There's more, but it's late. And I have to customize again (spoilers). If anyone wants more info, I'll post more. BTW, can we post links? Cause I could share the resources I had to cobble together to get the second install to work. And the Amazon link for the OTG.