What about performance ? Is Win10 running "faster" than Win7 ? On a x64 processor ?
For me, yes. The upgrade was automatically downloaded to my aging Lenovo G560 on Saturday. It had been running Windows 7 Home Premium until this point, though I did have Windows 8.1 Pro installed for about 6 months last year.
Visually, it is literally a mix of Windows 7 and Windows 8. Everything seems more responsive and feels noticeably faster. The Edge browser seems quicker out of the gate than Chrome (which in my opinion isn't saying much, since Chrome performance for me has been going downhill for the past year on all my machines). The G560 is also notorious for low sound volume from its Realtek HD speakers. It was apparently a driver issue, because there is at least a 30-40% increase in the volume output in Windows 10, which I didn't see when I had Windows 8.1 installed last year. All-in-all I have a good opinion of it. I think Microsoft got a lot of things right this time.