I'm running Windows 10 x64 on my 1012. The biggest performance issue I ran into was Windows Defender constantly slowing the computer down, sometimes to near freezes. You need to edit the registry to actually turn off Windows Defender, because it only stays turned off in the Settings for a short period before it automatically turns back on.
After permanently disabling it, the performance was and still is excellent compared to any other OS I have tried. I have also tried Ubuntu 14.04 LTS, Remix OS (32-bit), and OSX. None have performed as well as Windows 10 after having Windows Defender turned off.