I "upgraded" a PC running Windows 7 and a Surface 3 running Windows 8.1 to Windows 10 over the weekend. I thought that the PC would be more problematic because it had multiple users, older versions of Office, indeed older versions of everything. In practice the PC worked out fine (and I like Windows 10 on it) but the Surface is on its knees. None of Office 365 products work correctly. The minimise button works sporadically, the maximise/restore down button does not work at all. The close button sometimes closes the Office app, sometimes hangs the machine until something else is pressed ... Outlook in particular is almost impossible to use. In effect, each email opens in full screen and closing it loses the main Outlook window so it has become a one-time-use product each time its opened. The Edge browser on the Surface is much slower than on the PC and gets stuck regularly. No spinning circle, just nothing happens. The right "mouse" button hardly works at all. I can't find the really useful Search tool that I depended upon in Windows 8. If I had a Search tool maybe I could find it ... Unless someone can give me hope that these things are known about and are getting fixed, I have to revert to Windows 8.1 because I can't work like this. Longer term, even if these things are working, the tablet and touch concept of the Surface looks compromised. And as a senior IT professional I've been responsible for the purchase of hundreds of Windows mobile devices (phones and tablets) over the last two years. If I were looking for a new device today, I don't think a Windows 10 mobile device would get close to my buying radar.