[Device Reviews and Information] LuxZg:
OK, some feedback regarding my experiences with Chuwi Vi8 dual-boot last few days.

1) I've done a factory reset of both Windows 8.1 Bing and KitKat at the same time and did NOT run any setup wizzards or OOBE stuff. Done a backup with Macrium Reflect (awesome tool, thanks everyone for recommending it!), byte-for-byte image, with medium compression, of whole storage, and it's 6.05GB large. With verification it took 1 hour and few minutes I've been thinking about putting it online, but I assume I should first do a sysprep on Windows partition to clean the activation data (*unsure*).

2) I've setup both Android and Windows OS with just basic (account, uninstalled apps I don't need, setup wallpapers), and left Windows turned on and checked for updates a bit. Today I got offer through Windows Update to download and install Windows 10. Did that, simply allowed it to install. At 11AM it started download, at 11:30 it started install preparations, at noon I've accepted EULA and restarted it and at 1:15 PM I had activated and fully functional Windows 10 Home 32bit. All drivers, including touchscreen, worked just fine. I did not need SD card or USB stick, and used touchscreen for all steps of install which required user input. Not sure, but I guess I lost Office 365 1-year promo, it's not offering it anymore, but I can always bring back original image now that I have one. I have 1.5GB still left free, did not do the cleanup yet, but two folders I see that need deleting are 12GB (8GB size on disk). Recovery partition is still there (5,5GB).

Plans:

a) Once I do cleanup of W10, and maybe even another factory reset (there's no data on tablet anyway), I'll do one more Macrium Image, and than I'll see if I can gain extra space by deleting recovery partition altogether. I don't exactly need it for what I use on this tablet, but if I don't need recovery partition for OS to function, and I have several Macrium Images (at least 2 tested & verified by restore), than why not.

b) Also, I was thinking if you people want me to export all drivers from Windows 10 Home 32bit, as my OS is running just fine. I also have export of all drivers of original W8 Bing installation. Both exports done via PowerShell using this guide: http://woshub.com/how-to-export-drivers-using-powershell-in-windows-8-1-u1/ . Since I haven't installed ANY drivers myself, these are all either drivers from manufacturer or Microsoft.

c) Like I've said, I was thinking about making a clean Macrium Reflect image of tablet after W8 & KitKat are reset to factory defaults, maybe with addition of syspreped W8 installation. That should be ~6GB, I can upload that somewhere on my website or OneDrive

d) Same as c), I could do the factory reset of Kitkat and W10, again probably after sysprep. I assume it would be around same 6 maybe 7GB once compressed.

Few notes regarding Macrium Reflect images. I've restored tablet with it, and there are options to completely replace all data on drive, or do it per partition, all from same image, which is nice. So in case someone (like me) deletes Recovery partition, and Windows is not bootable anymore - only this one partition can be restored, no need to restore whole drive. Also, restoring takes a bit longer than creation, but I think it was no more than 1.5 hours when I did it.

Anyway, I'm open for feedback and suggestions, for now tablet is more or less in untouched state, I've had it only 2 weeks, and I have 3 Macrium Reflect images, plan to make 2-3 more "variations" of tablet in different states of OS install, and most I had on it were 2 test videos, few pictures & screenshots, and few Win8 "Metro"/"Universal" app games, so nothing that would influence either OS too much. While tablet is used like this, I can try something / upload something from it if anyone needs. I see most issues people report start with deleting partitions or updating drivers/OS, all of which can be fixed by restoring original partitions.

Oh, and for the end - I seriously recommend everyone that have this tablet (in working state) to make their own image of Chuwi's disk, it's quite simple, safe, and relatively quick, so 2 hours you'll invest in that will save you a lot of potential trouble and give you some peace of mind if anything bad happens with your "toy" :)