I'm having trouble understanding why you would buy an S3 with W10, and then wipe it and install W8.1? Why not just buy an S3 with W8.1 instead?
I got my S3 in Oct '15, and was installed with W8.1, so they were out there at the time. An8.1 might have been cheaper then a W10 as well.
If the Surface 3 was available to me with Win8.1 I would have taken it any day over the Win10 model- that way I would have had the privilege of choosing EITHER OS OFFICIALLY. But the thing is Surface 3 is not available in my country (only Surface Pro 4), I had to import it and there the only option I was being offered (I monitored this over a period of more than one month) was that of Windows 10. I imported it in late January but even if I had done it in, say, early December I would have gotten only the Win 10 version.
The trouble for me is- I run a proprietary software called Agile Key-in which is a front-end module for MIS, the back-end of which is SAP. It is a very intuitive & convenient software which makes it immensely easy to access information which otherwise would involve using/interacting with SAP directly. And considering that we run much less than the latest version of SAP that would be EXTREMELY cumbersome. Now, we do use SAP directly for umpteen tasks but this program was custom-developed for our organization to make it easier/convenient to use SAP for THAT PURPOSE which this software is designed for, even for people who aren't very well verse in the software. Even, if were proficient in trans versing the various vagaries of SAP it would have still been easier to use this software for it.
We have tried using all that is possible (include using VM) to run the current version of this program on Windows 10 but it just does not run. The developer is aware of that and promises to introduce a new version of it by late-2016, which for all intent means December.
I like Windows 10 a lot. I have run the Surface in desktop mode only (using the Surface Pro 4 Pen) since receiving it 3 weeks ago. And were it not for this one major, major hitch everything would have been perfect.