Just got my SP3 this past week. Used it for a couple of days with Windows 8.1, just get a feel for it. Then I did an upgrade to Windows 10 Build 10074. I've had no problems so far, except for Windows Mail occasionally shutting down when I click on a link within a message. Everything else is fully functional, including the One Note button on the top of the pen. I've even been able to use my network printer with no hiccups. Seems like a pretty good upgrade so far. Looking forward to the next level of Cortland, also.